fish disease?

[[email protected]]

Hi,

I have a yellow tailed blue damsel that appears to have lost all of
the blue coloring (scales?) at the top of his head and around his
eyes. So he's mostly blue, but black in that area. He's been that
way for about 3 weeks, but he eats well and is very active, and
otherwise normal. All water parameters are normal. Anyone have any
idea what this is? I'm aware it's just a $4 damsel, but I've had him
almost ten years and I'm upgrading from a FO tank to a bigger reef
setup, and I'd like to see him make the switch. Any help would be
appreciated.

Thanks,

Grant

[Wayne Sallee]

Could be nerve dammage. Nerve dammage will do that.

Wayne Sallee
Wayne's Pets



wrote on 2/10/2006 1:37 PM:
>
> Hi,
>
> I have a yellow tailed blue damsel that appears to have lost all of
> the blue coloring (scales?) at the top of his head and around his
> eyes. So he's mostly blue, but black in that area. He's been that
> way for about 3 weeks, but he eats well and is very active, and
> otherwise normal. All water parameters are normal. Anyone have any
> idea what this is? I'm aware it's just a $4 damsel, but I've had him
> almost ten years and I'm upgrading from a FO tank to a bigger reef
> setup, and I'd like to see him make the switch. Any help would be
> appreciated.
>
> Thanks,
>
> Grant

[Susan]

Wow, ten years!! That's great to keep livestock that long :)

Susan :)
"Wayne Sallee" > wrote in message
...
> Could be nerve dammage. Nerve dammage will do that.
>
> Wayne Sallee
> Wayne's Pets
>
>
>
> wrote on 2/10/2006 1:37 PM:
>>
>> Hi,
>>
>> I have a yellow tailed blue damsel that appears to have lost all of
>> the blue coloring (scales?) at the top of his head and around his
>> eyes. So he's mostly blue, but black in that area. He's been that
>> way for about 3 weeks, but he eats well and is very active, and
>> otherwise normal. All water parameters are normal. Anyone have any
>> idea what this is? I'm aware it's just a $4 damsel, but I've had him
>> almost ten years and I'm upgrading from a FO tank to a bigger reef
>> setup, and I'd like to see him make the switch. Any help would be
>> appreciated.
>>
>> Thanks,
>>
>> Grant

[Pszemol]

"Susan" > wrote in message m...
> Wow, ten years!! That's great to keep livestock that long :)

That is actually not unusuall for marine fish...
I read here, not that long ago, somebody here
kept his blue tang for something like 15-16 years.

[[email protected]]

Nerve damage? What could cause that?




On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee >
wrote:

>Could be nerve dammage. Nerve dammage will do that.
>
>Wayne Sallee
>Wayne's Pets

>
>
wrote on 2/10/2006 1:37 PM:
>>
>> Hi,
>>
>> I have a yellow tailed blue damsel that appears to have lost all of
>> the blue coloring (scales?) at the top of his head and around his
>> eyes. So he's mostly blue, but black in that area. He's been that
>> way for about 3 weeks, but he eats well and is very active, and
>> otherwise normal. All water parameters are normal. Anyone have any
>> idea what this is? I'm aware it's just a $4 damsel, but I've had him
>> almost ten years and I'm upgrading from a FO tank to a bigger reef
>> setup, and I'd like to see him make the switch. Any help would be
>> appreciated.
>>
>> Thanks,
>>
>> Grant

[George Patterson]

wrote:

> I have a yellow tailed blue damsel that appears to have lost all of
> the blue coloring (scales?) at the top of his head and around his
> eyes. So he's mostly blue, but black in that area.

Electrical leakage into the tank can cause this sort of thing. If all your
submerged equipment is on a GFCI outlet, this is almost certainly not the cause.
If you don't have a GFCI, get one. If it trips, unplug equipment and reset until
it doesn't trip. Replace the last item you unplugged.

If this is the cause, the scales may not regrow, but the fish will be ok.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[[email protected]]

On Mon, 13 Feb 2006 03:58:09 GMT, George Patterson
> wrote:

wrote:
>
>> I have a yellow tailed blue damsel that appears to have lost all of
>> the blue coloring (scales?) at the top of his head and around his
>> eyes. So he's mostly blue, but black in that area.
>
>Electrical leakage into the tank can cause this sort of thing. If all your
>submerged equipment is on a GFCI outlet, this is almost certainly not the cause.
>If you don't have a GFCI, get one. If it trips, unplug equipment and reset until
>it doesn't trip. Replace the last item you unplugged.
>
>If this is the cause, the scales may not regrow, but the fish will be ok.
>
>George Patterson
> Coffee is only a way of stealing time that should by rights belong to
> your slightly older self.

George,

All tank equipment is on a GFCI outlet. However, I live in an old
house. Most of the circuits are knob and tube style wiring. The
tank's circuit, as well as a few others, are updated wiring, but the
electrical panel is not grounded to anything. Is my GFCI useless?
What about a grounding probe? And is this the most likely cause of
the problem. Thanks for your input.

Grant

[Mark Henry]

>
> All tank equipment is on a GFCI outlet. However, I live in an old
> house. Most of the circuits are knob and tube style wiring. The
> tank's circuit, as well as a few others, are updated wiring, but the
> electrical panel is not grounded to anything. Is my GFCI useless?
> What about a grounding probe? And is this the most likely cause of
> the problem. Thanks for your input.
>

Who installed the GFCI? If it was a qualified electrician then there's
got to be a gounding line in the panel that it's conneted to.

mark h

[George Patterson]

wrote:

> All tank equipment is on a GFCI outlet. However, I live in an old
> house. Most of the circuits are knob and tube style wiring. The
> tank's circuit, as well as a few others, are updated wiring, but the
> electrical panel is not grounded to anything. Is my GFCI useless?

No. GFCI outlets are frequently used with obsolete wiring to provide the safety
equivalent of a grounded circuit. It will work just fine. If one of your pieces
of equipment were leaking current into the water, the GFCI would trip.

One more thing. Your electrical panel is almost certainly actually grounded to
something (I've never seen one that isn't). Prior to about 1970, it was common
practice to ground the box to the cold water supply line. These days, they sink
one or two heavy copper rods 8' into the ground and run a wire to them. It's
possible that the original ground wire was removed, especially if plumbing lines
have been re-routed.

> What about a grounding probe? And is this the most likely cause of
> the problem. Thanks for your input.

I use a probe on my tank, but I think it's unecessary if you have a GFCI (I put
mine in before I got a GFCI). From what I've read, the most likely cause of the
symptoms you describe is some sort of bacterial infection, but it doesn't have
all of the symptoms of the most common infections (for one thing, these are
usually white and cause tissue loss). Infections are hard to treat, since it's
hard to tell what antibiotic will work on your particular disease. You also
can't just dump a bunch of antibiotics in a reef tank.

Perhaps it's just old age?

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[George Patterson]

Mark Henry wrote:

> Who installed the GFCI? If it was a qualified electrician then there's
> got to be a gounding line in the panel that it's conneted to.

GFCIs are frequently installed on ungrounded circuits for safety upgrades. It's
much cheaper than running a ground wire.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Pszemol]

"George Patterson" > wrote in message news:p81If.23857$Eq.13398@trnddc02...
> wrote:
> If one of your pieces of equipment were leaking current into the water, the GFCI would trip.

You are correct, but it is important to know, it does not work like "all or nothing".

All GFCI are rated with a leak current detection threshold - they trip if the leak
current is bigger than a threshold and continue to work normally if the leaking
current is below the threshold. For many GFCI this threshold is set to the level
of 20-30mA. This is quite a strong current causing pain and musscle retraction
when applied to human skin. The purpose is not to kill a user only... but you
might still get zapped quite seriously and painful before the GFCI will trip.

And, what is more important in our aquarium applications: small currents
(below the threshold) continue to leak without being detected by GFCI...
So you can clearly have, lets say 5-10mA current leaking from your powerhead
failing insulation and your GFCI will do nothing to stop it. Will your fish feel it ?
We would need to ask them ;-)

[Wayne Sallee]

It can be caused by injuries. I've seen it most often in
african cichlids.

Wayne Sallee
Wayne's Pets



wrote on 2/12/2006 10:20 PM:
> Nerve damage? What could cause that?
>
>
>
>
> On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee >
> wrote:
>
>
>>Could be nerve dammage. Nerve dammage will do that.
>>
>>Wayne Sallee
>>Wayne's Pets

>>
>>
wrote on 2/10/2006 1:37 PM:
>>
>>>
>>>Hi,
>>>
>>>I have a yellow tailed blue damsel that appears to have lost all of
>>>the blue coloring (scales?) at the top of his head and around his
>>>eyes. So he's mostly blue, but black in that area. He's been that
>>>way for about 3 weeks, but he eats well and is very active, and
>>>otherwise normal. All water parameters are normal. Anyone have any
>>>idea what this is? I'm aware it's just a $4 damsel, but I've had him
>>>almost ten years and I'm upgrading from a FO tank to a bigger reef
>>>setup, and I'd like to see him make the switch. Any help would be
>>>appreciated.
>>>
>>>Thanks,
>>>
>>>Grant
>
>

[Wayne Sallee]

Also the nerve damage I have seen has involved the change
of skin color, rather than missing scales.

Wayne Sallee
Wayne's Pets



Wayne Sallee wrote on 2/13/2006 5:49 PM:
> It can be caused by injuries. I've seen it most often in african cichlids.
>
> Wayne Sallee
> Wayne's Pets
>
>
>
> wrote on 2/12/2006 10:20 PM:
>
>> Nerve damage? What could cause that?
>>
>>
>>
>>
>> On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee >
>> wrote:
>>
>>
>>> Could be nerve dammage. Nerve dammage will do that.
>>>
>>> Wayne Sallee
>>> Wayne's Pets
>>>
>>>
>>>
>>> wrote on 2/10/2006 1:37 PM:
>>>
>>>>
>>>> Hi,
>>>>
>>>> I have a yellow tailed blue damsel that appears to have lost all of
>>>> the blue coloring (scales?) at the top of his head and around his
>>>> eyes. So he's mostly blue, but black in that area. He's been that
>>>> way for about 3 weeks, but he eats well and is very active, and
>>>> otherwise normal. All water parameters are normal. Anyone have any
>>>> idea what this is? I'm aware it's just a $4 damsel, but I've had him
>>>> almost ten years and I'm upgrading from a FO tank to a bigger reef
>>>> setup, and I'd like to see him make the switch. Any help would be
>>>> appreciated.
>>>>
>>>> Thanks,
>>>>
>>>> Grant
>>
>>
>>

[[email protected]]

In answer to the previous questions, Mark, I installed the GFCI. I'm
not a qualified electrician--I know just enough to be dangerous.
They're easy to install, though. George, believe it or not, there's
no ground. No ground rod outside, no cold water ground, nothing. The
house was built in 1927 and I've owned it for 5 years. I've meant to
install one, just never have. Pszemol, in your opinion, a ground
probe can't hurt, even if it's somewhat redundant with the GFCI and
may actually be beneficial, correct? Wayne, it could be an injury.
He has a tomato clown pestering him constantly, but it's been that way
for years.

I guess that without a definite cause, I'll try to treat him through
process of elimination and see what works. Everyone, thanks for your
help, and any additional thoughts would be welcome.

Grant


On Mon, 13 Feb 2006 23:29:17 GMT, Wayne Sallee >
wrote:

>Also the nerve damage I have seen has involved the change
>of skin color, rather than missing scales.
>
>Wayne Sallee
>Wayne's Pets

>
>
>Wayne Sallee wrote on 2/13/2006 5:49 PM:
>> It can be caused by injuries. I've seen it most often in african cichlids.
>>
>> Wayne Sallee
>> Wayne's Pets
>>
>>
>>
>> wrote on 2/12/2006 10:20 PM:
>>
>>> Nerve damage? What could cause that?
>>>
>>>
>>>
>>>
>>> On Sat, 11 Feb 2006 22:11:05 GMT, Wayne Sallee >
>>> wrote:
>>>
>>>
>>>> Could be nerve dammage. Nerve dammage will do that.
>>>>
>>>> Wayne Sallee
>>>> Wayne's Pets
>>>>
>>>>
>>>>
>>>> wrote on 2/10/2006 1:37 PM:
>>>>
>>>>>
>>>>> Hi,
>>>>>
>>>>> I have a yellow tailed blue damsel that appears to have lost all of
>>>>> the blue coloring (scales?) at the top of his head and around his
>>>>> eyes. So he's mostly blue, but black in that area. He's been that
>>>>> way for about 3 weeks, but he eats well and is very active, and
>>>>> otherwise normal. All water parameters are normal. Anyone have any
>>>>> idea what this is? I'm aware it's just a $4 damsel, but I've had him
>>>>> almost ten years and I'm upgrading from a FO tank to a bigger reef
>>>>> setup, and I'd like to see him make the switch. Any help would be
>>>>> appreciated.
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Grant
>>>
>>>
>>>

[George Patterson]

wrote:

> .... a ground
> probe can't hurt, even if it's somewhat redundant with the GFCI and
> may actually be beneficial, correct?

The ground rod will help if you have a trickle leak into the tank (at least it
did on my tank). It may also have the additional benefit of causing the
defective piece of equipment to give up the ghost (again, it did in my tank).

It might be better to find out if you have a current leak, however. Buy or
borrow a decent volt/amp meter (Radio Shack is one source). Hook one lead to a
good ground and stick the other in the tank. Set it for alternating current and
see if it reads anything. I've not done this for my tank, but someone in this
group suggested it the last time this subject surfaced.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[George Patterson]

Pszemol wrote:

> Grounding probe, increasing leakage currents, will push
> the small currents above triping threshold of the GFCI,
> (only if GFCI installed).

If that's the case (and I'm not saying it isn't - your logic sounds good), then
the addition of a grounding probe would help determine which equipment (if any)
is faulty. Just unplug things until the GFCI doesn't trip.

> I would be glad if some intelligent electrician explain this to me
> and I could understand this way why people use g-probes for HLLD...

Well, I'm trained as an electrician (among other things) and do electrical work
(among other things). Quite a few people are of the opinion that I'm
intelligent. That doesn't mean that I understand why grounding the tank will
help with HLLD. All I know about it is that one of my fish developed HLLD
several years ago. A guy at an LFS told me a ground probe would cure it. I
installed one, and shortly thereafter, one of my powerheads bit the dust. The
fish slowly improved after that.

I believe that the ground probe did, as you suggest, increase the current flow,
causing the marginally faulty powerhead to fail. I further believe that the LFS
clerk was correct that the current leak into the water was causing the HLLD.

Like you, I don't see how a ground probe can help with HLLD as long as current
is free in the tank. I think it helps only by causing the current source to
fail, which stops the current flow.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Pszemol]

"George Patterson" > wrote in message news:VteIf.21439$0H1.11817@trnddc04...
> If that's the case (and I'm not saying it isn't - your logic sounds good), then
> the addition of a grounding probe would help determine which equipment
> (if any) is faulty. Just unplug things until the GFCI doesn't trip.

Correct.
But, a device might be faulty in such a way, that will leak the current
small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
In this case, adding grounding probe will cause stray current which
would not exists if you consider high impedance of glass and stand.
(by "not exists" I mean in practical way, lets say it would be 100pA or 1nA)

> That doesn't mean that I understand why grounding the tank will
> help with HLLD. All I know about it is that one of my fish developed HLLD
> several years ago. A guy at an LFS told me a ground probe would cure it. I
> installed one, and shortly thereafter, one of my powerheads bit the dust. The
> fish slowly improved after that.

Interesting, but still only an anegdotal evidence...

> I believe that the ground probe did, as you suggest, increase the current flow,
> causing the marginally faulty powerhead to fail. I further believe that the LFS
> clerk was correct that the current leak into the water was causing the HLLD.
>
> Like you, I don't see how a ground probe can help with HLLD as long as
> current is free in the tank. I think it helps only by causing the current source
> to fail, which stops the current flow.

I do not understand the expression "current is free in the tank"...
Must be some secret electricians lingo ;-)

My problem with understanding stray *voltages* (not currents) affecting
fish health is that voltage means NOTHING if you do not relate it
to some other potential, like ground. The way to "relate" a potential
of one point (water) to the second point (ground) is to use g-probe.

Try to understand my point here:
when you measure voltage, and you read 120V, it means that
the potential BETWEEN TWO POINTS of the circuit is 120V.
It is assumed, for most cases, that the second point of reference
is ground, but it is not always a case - see birds sitting on a HV wire
example. They do not care how big potential is between the wire they
sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
For that matter, you could measure potential of this wire to whatever
other conductor you like and get a reading from 0 to a milion volts
and birds would not care... Same should apply to fish in the glass
insulated tank... But somehow it does not. At least anegdotal
evidence shows that stray voltages matter for HLLD - but why ?

And this is a part of the story difficult to understand - help! Anybody ?

[George Patterson]

Pszemol wrote:

> Correct. But, a device might be faulty in such a way, that will leak the
> current
> small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!

To clarify: You said earlier that a grounding probe "will actually INCREASE
the leakage currents flowing from the electrical devices!" If that is the case,
the flow would be more likely to trip the GFCI.

George Patterson
Coffee is only a way of stealing time that should by rights belong to
your slightly older self.

[Pszemol]

"George Patterson" > wrote in message news:P8nIf.25374$Eq.20667@trnddc02...
>> Correct. But, a device might be faulty in such a way, that will leak the
>> current
>> small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
>
> To clarify: You said earlier that a grounding probe "will actually INCREASE
> the leakage currents flowing from the electrical devices!" If that is the case,
> the flow would be more likely to trip the GFCI.

Let me explain again using examples as ilustrations this time:


Case 1: we have faulty powerhead - no grounding probe.
Insulator in the powerhead is leaking current to the water.
So the water column is under voltage to the ground/floor...
Due to the high impedance of glass and wooden stand
the current is limited to, lets say 2uA. GFCI does not trip
but the current flows and fish are affected...

After adding grounding probe, high impedance of glass
and wooden stand (acting as a current limiting insulator)
is bypassed and the whole leakage current is lead to ground
through the probe. The current increases and reaches
threshold which trips GFCI.


We replace the faulty powerhead with a good one and relax... :-)


Case 2: good powerhead with acceptable insulator, lets
say 100Mohms. This impedance 100Mohms will add to
equally high or higher impedance of glass and wooden
canopy and the stray, parasitic current flowing through the water
at 120V will be negligible. lets say 1/4 of a microamp (0.25uA).

After adding the grounding probe, high impedance of glass
and wooden stand is bypassed again, and the current is
limited ONLY by the powerhead insulator, this 100Mohms.
So adding grounding probe WILL INCREASE this stray
current to 120V/120Mohms = ~1uA. This current is too small
to trip the GFCI but the current flows and fish are affected.


Of course - every powerhead is different, they all will have
different insulator properties, they all will have different ways
to go bad etc... What I wrote above is just an example.
Note: adding a grounding probe to a good working tank might
increase stray currents to levels existing in a tank with faulty
electrical devices when no probe is installed... Go figure! :-)

[Wayne Sallee]

You are correct Pszemol.

Grounding probes do not make things better for the fish.
The only thing that they do is protect the person, but
this is not why people install grounding probes.

The easyest thing to do is to get a vohm meter, and test
for leaking voltage, if votage is found, then unplug
everything, and then replug in stuff one at a time to find
out what is leaking.

Now the ideal system to do what people are wanting (but
too expensive) would be a computer that would moniter for
voltage, but in it's monitoring would only take in a small
amount of miliamps, then would present an alarm if such
voltage was found, and would selectively turn off all
items, and then turn on each item at a time to find out
wich item was leeking, and disable that item, and send an
alarm and declare wich item is bad. Naturaly this would be
a very expensive system. And you would have to decide what
amount of voltage leakage would warent shutting down the
item in your absents.

A simpler system would be something that would check for
voltage, taking in only a small amount of milivolts and
give an alarm when voltage is detected, allowing the
person to find the problem.

GFI systems only stop large amounts of electricity
leakage. Puting a ground probe will prevent you from
noticing small leakage of electricity when you put your
hands in the tank, or vohm meter in the tank.

Wayne Sallee
Wayne's Pets



Pszemol wrote on 2/14/2006 10:23 AM:
> "George Patterson" > wrote in message
> news:VteIf.21439$0H1.11817@trnddc04...
>
>> If that's the case (and I'm not saying it isn't - your logic sounds
>> good), then the addition of a grounding probe would help determine
>> which equipment
>> (if any) is faulty. Just unplug things until the GFCI doesn't trip.
>
>
> Correct. But, a device might be faulty in such a way, that will leak the
> current
> small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
> In this case, adding grounding probe will cause stray current which
> would not exists if you consider high impedance of glass and stand.
> (by "not exists" I mean in practical way, lets say it would be 100pA or
> 1nA)
>
>> That doesn't mean that I understand why grounding the tank will help
>> with HLLD. All I know about it is that one of my fish developed HLLD
>> several years ago. A guy at an LFS told me a ground probe would cure
>> it. I installed one, and shortly thereafter, one of my powerheads bit
>> the dust. The fish slowly improved after that.
>
>
> Interesting, but still only an anegdotal evidence...
>
>> I believe that the ground probe did, as you suggest, increase the
>> current flow, causing the marginally faulty powerhead to fail. I
>> further believe that the LFS clerk was correct that the current leak
>> into the water was causing the HLLD.
>>
>> Like you, I don't see how a ground probe can help with HLLD as long as
>> current is free in the tank. I think it helps only by causing the
>> current source
>> to fail, which stops the current flow.
>
>
> I do not understand the expression "current is free in the tank"...
> Must be some secret electricians lingo ;-)
>
> My problem with understanding stray *voltages* (not currents) affecting
> fish health is that voltage means NOTHING if you do not relate it
> to some other potential, like ground. The way to "relate" a potential
> of one point (water) to the second point (ground) is to use g-probe.
>
> Try to understand my point here:
> when you measure voltage, and you read 120V, it means that
> the potential BETWEEN TWO POINTS of the circuit is 120V.
> It is assumed, for most cases, that the second point of reference
> is ground, but it is not always a case - see birds sitting on a HV wire
> example. They do not care how big potential is between the wire they
> sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
> For that matter, you could measure potential of this wire to whatever
> other conductor you like and get a reading from 0 to a milion volts
> and birds would not care... Same should apply to fish in the glass
> insulated tank... But somehow it does not. At least anegdotal
> evidence shows that stray voltages matter for HLLD - but why ?
>
> And this is a part of the story difficult to understand - help! Anybody ?

[Wayne Sallee]

There are a few places here where I refered to voltage,
when amperage would have been a better word, but you get
what I'm saying.

Wayne Sallee
Wayne's Pets



Wayne Sallee wrote on 2/14/2006 11:42 AM:
> You are correct Pszemol.
>
> Grounding probes do not make things better for the fish. The only thing
> that they do is protect the person, but this is not why people install
> grounding probes.
>
> The easyest thing to do is to get a vohm meter, and test for leaking
> voltage, if votage is found, then unplug everything, and then replug in
> stuff one at a time to find out what is leaking.
>
> Now the ideal system to do what people are wanting (but too expensive)
> would be a computer that would moniter for voltage, but in it's
> monitoring would only take in a small amount of miliamps, then would
> present an alarm if such voltage was found, and would selectively turn
> off all items, and then turn on each item at a time to find out wich
> item was leeking, and disable that item, and send an alarm and declare
> wich item is bad. Naturaly this would be a very expensive system. And
> you would have to decide what amount of voltage leakage would warent
> shutting down the item in your absents.
>
> A simpler system would be something that would check for voltage, taking
> in only a small amount of milivolts and give an alarm when voltage is
> detected, allowing the person to find the problem.
>
> GFI systems only stop large amounts of electricity leakage. Puting a
> ground probe will prevent you from noticing small leakage of electricity
> when you put your hands in the tank, or vohm meter in the tank.
>
> Wayne Sallee
> Wayne's Pets
>
>
>
> Pszemol wrote on 2/14/2006 10:23 AM:
>
>> "George Patterson" > wrote in message
>> news:VteIf.21439$0H1.11817@trnddc04...
>>
>>> If that's the case (and I'm not saying it isn't - your logic sounds
>>> good), then the addition of a grounding probe would help determine
>>> which equipment
>>> (if any) is faulty. Just unplug things until the GFCI doesn't trip.
>>
>>
>>
>> Correct. But, a device might be faulty in such a way, that will leak
>> the current
>> small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
>> In this case, adding grounding probe will cause stray current which
>> would not exists if you consider high impedance of glass and stand.
>> (by "not exists" I mean in practical way, lets say it would be 100pA
>> or 1nA)
>>
>>> That doesn't mean that I understand why grounding the tank will help
>>> with HLLD. All I know about it is that one of my fish developed HLLD
>>> several years ago. A guy at an LFS told me a ground probe would cure
>>> it. I installed one, and shortly thereafter, one of my powerheads bit
>>> the dust. The fish slowly improved after that.
>>
>>
>>
>> Interesting, but still only an anegdotal evidence...
>>
>>> I believe that the ground probe did, as you suggest, increase the
>>> current flow, causing the marginally faulty powerhead to fail. I
>>> further believe that the LFS clerk was correct that the current leak
>>> into the water was causing the HLLD.
>>>
>>> Like you, I don't see how a ground probe can help with HLLD as long as
>>> current is free in the tank. I think it helps only by causing the
>>> current source
>>> to fail, which stops the current flow.
>>
>>
>>
>> I do not understand the expression "current is free in the tank"...
>> Must be some secret electricians lingo ;-)
>>
>> My problem with understanding stray *voltages* (not currents) affecting
>> fish health is that voltage means NOTHING if you do not relate it
>> to some other potential, like ground. The way to "relate" a potential
>> of one point (water) to the second point (ground) is to use g-probe.
>>
>> Try to understand my point here:
>> when you measure voltage, and you read 120V, it means that
>> the potential BETWEEN TWO POINTS of the circuit is 120V.
>> It is assumed, for most cases, that the second point of reference
>> is ground, but it is not always a case - see birds sitting on a HV wire
>> example. They do not care how big potential is between the wire they
>> sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
>> For that matter, you could measure potential of this wire to whatever
>> other conductor you like and get a reading from 0 to a milion volts
>> and birds would not care... Same should apply to fish in the glass
>> insulated tank... But somehow it does not. At least anegdotal
>> evidence shows that stray voltages matter for HLLD - but why ?
>>
>> And this is a part of the story difficult to understand - help! Anybody ?

[Boomer]

Wayne, George and Pszemol

Before you guys get off on a meanlingess tangent plaese read these


http://article.dphnet.com/cat-02/strayvoltages.shtml

http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GroundingProbes.html

http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GFI&TechnicalDetails.html


The Hammer & Deep-Sixer
http://www.reefs.org/library/aquarium_net/1298/1298_3.html



Research

Does Stray Voltage Effect Fish?
Canadian fish farmers claim that stray low voltage levels reduce growth of farmed fish.
Researchers set out to find if stray voltage did have an effect on fish. They selected
hatchery-raised rainbow trout Oncorhynchus mykiss for the study. The tests showed no
effect of electrical fields (5, 50, 500 & 5000 mV/m) on the hatching and development of
fry. Other tests on larger trout showed normal growth rate and survival after exposure to
stray voltage for up to 10 weeks.

Their conclusion? Stray electrical fields have no effect on rainbow trout. Complete
details of the experiment can be found in: Brouard, B., Harvey, C., Goulet, D., Nguyen,
T.,Champagne, R. and P. Dube. Evaluation of potential effects of stray voltage generated
by alternating current on hatchery-raised rainbow trout. The Progressive Fish Culturist
58:47-51,1996.



This one or anything like it is a line of BS. At one time, years ago, I also believed it.

http://animal-world.com/encyclo/fishnchips/sept00/fnc0900.html#voltage

--
Boomer

If You See Me Running You Better Catch-Up

Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ! The Coral Realm
http://www.coralrealm.com



"Wayne Sallee" > wrote in message
...
: You are correct Pszemol.
:
: Grounding probes do not make things better for the fish.
: The only thing that they do is protect the person, but
: this is not why people install grounding probes.
:
: The easyest thing to do is to get a vohm meter, and test
: for leaking voltage, if votage is found, then unplug
: everything, and then replug in stuff one at a time to find
: out what is leaking.
:
: Now the ideal system to do what people are wanting (but
: too expensive) would be a computer that would moniter for
: voltage, but in it's monitoring would only take in a small
: amount of miliamps, then would present an alarm if such
: voltage was found, and would selectively turn off all
: items, and then turn on each item at a time to find out
: wich item was leeking, and disable that item, and send an
: alarm and declare wich item is bad. Naturaly this would be
: a very expensive system. And you would have to decide what
: amount of voltage leakage would warent shutting down the
: item in your absents.
:
: A simpler system would be something that would check for
: voltage, taking in only a small amount of milivolts and
: give an alarm when voltage is detected, allowing the
: person to find the problem.
:
: GFI systems only stop large amounts of electricity
: leakage. Puting a ground probe will prevent you from
: noticing small leakage of electricity when you put your
: hands in the tank, or vohm meter in the tank.
:
: Wayne Sallee
: Wayne's Pets
:
:
:
: Pszemol wrote on 2/14/2006 10:23 AM:
: > "George Patterson" > wrote in message
: > news:VteIf.21439$0H1.11817@trnddc04...
: >
: >> If that's the case (and I'm not saying it isn't - your logic sounds
: >> good), then the addition of a grounding probe would help determine
: >> which equipment
: >> (if any) is faulty. Just unplug things until the GFCI doesn't trip.
: >
: >
: > Correct. But, a device might be faulty in such a way, that will leak the
: > current
: > small enough to not trip the GFCI (lets say 10mA for a 20mA GFCI)!
: > In this case, adding grounding probe will cause stray current which
: > would not exists if you consider high impedance of glass and stand.
: > (by "not exists" I mean in practical way, lets say it would be 100pA or
: > 1nA)
: >
: >> That doesn't mean that I understand why grounding the tank will help
: >> with HLLD. All I know about it is that one of my fish developed HLLD
: >> several years ago. A guy at an LFS told me a ground probe would cure
: >> it. I installed one, and shortly thereafter, one of my powerheads bit
: >> the dust. The fish slowly improved after that.
: >
: >
: > Interesting, but still only an anegdotal evidence...
: >
: >> I believe that the ground probe did, as you suggest, increase the
: >> current flow, causing the marginally faulty powerhead to fail. I
: >> further believe that the LFS clerk was correct that the current leak
: >> into the water was causing the HLLD.
: >>
: >> Like you, I don't see how a ground probe can help with HLLD as long as
: >> current is free in the tank. I think it helps only by causing the
: >> current source
: >> to fail, which stops the current flow.
: >
: >
: > I do not understand the expression "current is free in the tank"...
: > Must be some secret electricians lingo ;-)
: >
: > My problem with understanding stray *voltages* (not currents) affecting
: > fish health is that voltage means NOTHING if you do not relate it
: > to some other potential, like ground. The way to "relate" a potential
: > of one point (water) to the second point (ground) is to use g-probe.
: >
: > Try to understand my point here:
: > when you measure voltage, and you read 120V, it means that
: > the potential BETWEEN TWO POINTS of the circuit is 120V.
: > It is assumed, for most cases, that the second point of reference
: > is ground, but it is not always a case - see birds sitting on a HV wire
: > example. They do not care how big potential is between the wire they
: > sit on and the ground BECAUSE THEY DO NOT TOUCH THE GROUND.
: > For that matter, you could measure potential of this wire to whatever
: > other conductor you like and get a reading from 0 to a milion volts
: > and birds would not care... Same should apply to fish in the glass
: > insulated tank... But somehow it does not. At least anegdotal
: > evidence shows that stray voltages matter for HLLD - but why ?
: >
: > And this is a part of the story difficult to understand - help! Anybody ?

[Pszemol]

"Boomer" > wrote in message ...
> Wayne, George and Pszemol
>
> Before you guys get off on a meanlingess tangent plaese read these
>
>
> http://article.dphnet.com/cat-02/strayvoltages.shtml

Generaly agree with the author and if he celaned this text
from several typographic errors and mistakes it would be cool.
Right now some person not familiar with material would not catch
the mistakes and mix 40.0 ohms with 40 mega-ohms or disconnects
HOT from the pump to expect some stray voltages in the tank...

One thing I disagee with the author. It is "grounding probes"
is the must and we can do nothing about this stray voltages
causing stray currents. I think we can use a properly sized
isulation/safety transformer instead of GFCI+probe duet and
do a much better job in securing the tank and increasing safety
of the tank equiped with electrical devices. With relatively
not high prices of such transformers (compared to other equipment
we use in our reef tanks) this option is worth considering.
I would check with a local stores like RadioShack, Fry's
Electronics or similar and ask for isulation or safety transformer.
More popular are "voltage converting" transformers (120V->220V
and vice-versa) but the kind having 1:1 ratio are also available.
Really huge ones, 1000W would run for something about $150-$200.
For smaller applications half the size should be enough - just
add all devices rated power in watts together and size the
transformer for the next bigger one. With transformer you will
have no stray voltages, no risk of electricution and no g-probe
required anymore...

> http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GroundingProbes.html
>
> http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GFI&TechnicalDetails.html

The example with mechanical coupling of motor and generator is
misleading... GFCI does not trip when it will detect leak to ground.
It trips where there is a difference between hot and neutral current
flows. GFCI will trip and protect a person from being killed by
faulty device leaking current to the water even if there is no
grounding probe in the aquarium. But without the probe, aquarium
will remain charged and the GFCI would wait for you, aquarist,
to put your hand into the water before it would trip disconnecting
the circuit... You would feel zapped, maybe even little painful
(depending of the GFCI threshold current) but you will not get killed.
And this is the role of GFCI. Grounding probe would trip the circuit
with or without your hand in the water - so when you put your hand
in the water your aquarium would be running long time without AC
electricity and your fish most likely would suffocate due to lack
of circulation/oxygenation - that is the only difference :-)

> Their conclusion? Stray electrical fields have no effect on rainbow trout. Complete
> details of the experiment can be found in: Brouard, B., Harvey, C., Goulet, D., Nguyen,
> T.,Champagne, R. and P. Dube. Evaluation of potential effects of stray voltage generated
> by alternating current on hatchery-raised rainbow trout. The Progressive Fish Culturist
> 58:47-51,1996.

Cool!

[Boomer]

PZE

Any commens on the other article ? You gave no reply to this one :-)

The Hammer & Deep-Sixer
http://www.reefs.org/library/aquarium_net/1298/1298_3.html


--
Boomer

If You See Me Running You Better Catch-Up

Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ! The Coral Realm
http://www.coralrealm.com



"Pszemol" > wrote in message ...
: "Boomer" > wrote in message ...
: > Wayne, George and Pszemol
: >
: > Before you guys get off on a meanlingess tangent plaese read these
: >
: >
: > http://article.dphnet.com/cat-02/strayvoltages.shtml
:
: Generaly agree with the author and if he celaned this text
: from several typographic errors and mistakes it would be cool.
: Right now some person not familiar with material would not catch
: the mistakes and mix 40.0 ohms with 40 mega-ohms or disconnects
: HOT from the pump to expect some stray voltages in the tank...
:
: One thing I disagee with the author. It is "grounding probes"
: is the must and we can do nothing about this stray voltages
: causing stray currents. I think we can use a properly sized
: isulation/safety transformer instead of GFCI+probe duet and
: do a much better job in securing the tank and increasing safety
: of the tank equiped with electrical devices. With relatively
: not high prices of such transformers (compared to other equipment
: we use in our reef tanks) this option is worth considering.
: I would check with a local stores like RadioShack, Fry's
: Electronics or similar and ask for isulation or safety transformer.
: More popular are "voltage converting" transformers (120V->220V
: and vice-versa) but the kind having 1:1 ratio are also available.
: Really huge ones, 1000W would run for something about $150-$200.
: For smaller applications half the size should be enough - just
: add all devices rated power in watts together and size the
: transformer for the next bigger one. With transformer you will
: have no stray voltages, no risk of electricution and no g-probe
: required anymore...
:
: > http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GroundingProbes.html
: >
: > http://avdil.gtri.gatech.edu/RCM/RCM/Aquarium/GFI&TechnicalDetails.html
:
: The example with mechanical coupling of motor and generator is
: misleading... GFCI does not trip when it will detect leak to ground.
: It trips where there is a difference between hot and neutral current
: flows. GFCI will trip and protect a person from being killed by
: faulty device leaking current to the water even if there is no
: grounding probe in the aquarium. But without the probe, aquarium
: will remain charged and the GFCI would wait for you, aquarist,
: to put your hand into the water before it would trip disconnecting
: the circuit... You would feel zapped, maybe even little painful
: (depending of the GFCI threshold current) but you will not get killed.
: And this is the role of GFCI. Grounding probe would trip the circuit
: with or without your hand in the water - so when you put your hand
: in the water your aquarium would be running long time without AC
: electricity and your fish most likely would suffocate due to lack
: of circulation/oxygenation - that is the only difference :-)
:
: > Their conclusion? Stray electrical fields have no effect on rainbow trout. Complete
: > details of the experiment can be found in: Brouard, B., Harvey, C., Goulet, D.,
Nguyen,
: > T.,Champagne, R. and P. Dube. Evaluation of potential effects of stray voltage
generated
: > by alternating current on hatchery-raised rainbow trout. The Progressive Fish
Culturist
: > 58:47-51,1996.
:
: Cool!

[Pszemol]

"Boomer" > wrote in message ...
> PZE
>
> Any commens on the other article ? You gave no reply to this one :-)
>
> The Hammer & Deep-Sixer
> http://www.reefs.org/library/aquarium_net/1298/1298_3.html

No comments, because I have not read it yet :-)
Are you interested in my comments ?

[Boomer]

"Are you interested in my comments ?"


Yes

Is your background electrical ? IDNR

--
Boomer

If You See Me Running You Better Catch-Up

Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ! The Coral Realm
http://www.coralrealm.com



"Pszemol" > wrote in message ...
: "Boomer" > wrote in message
...
: > PZE
: >
: > Any commens on the other article ? You gave no reply to this one :-)
: >
: > The Hammer & Deep-Sixer
: > http://www.reefs.org/library/aquarium_net/1298/1298_3.html
:
: No comments, because I have not read it yet :-)
: Are you interested in my comments ?

[Pszemol]

"Boomer" > wrote in message ...
> "Are you interested in my comments ?"
>
> Yes
>
> Is your background electrical ? IDNR

As I have clearly stated in my previous writing
)
I am not an electrician I am electronic engineer.
You know... transistors, microprocessors, resistors also software etc ;-)

[~Roy~]

Pszemol........your what I am trying to learn overnight just so I can
assemble some moon lights and other projects. I am totally lost (yet
again) with al the formulas etc. Evidently there is much more to just
grabbing a wall wart and a led and usuing the online resistor / array
calculator to determine the resistor and wiring it all up. Yea it
may work but for how long. Yet all you see on thre DIY pages in the
multitude of sal****er forums thats all most of them do, and i fit
lights up its a sucess. Its manna from heaven to the followers.

I am slowly getting there, as its been over 35 years or more since I
took some basic electronics in a military tech school, and after I got
out of that school, I never had the need or opportunity to use what I
had learned.....so needless to say I am very rusty at pulling out the
info from my head.

Right now I am trying to figure out what size resistor I need to drop
the volts and such down on the varous wal warts I have. For example I
have 7 brand new Nokia cell phone chargers....that are labeled as
350ma 3.7 volts. Online array wizzard shows a resistor of 1/4 w and
6.8 ohms is needed to be used with a 3.5 forward volt 30 ma LED....But
when I hooked it all up th eled blew out after a short time.....I
checked voltage on the wall wart and its actually putting out 7.9
volts open circuit. So I am working on figuring out what size resistor
I need to eat up the excess voltage and get me down to 3.5 volts and
hopefully 20 or 25 ma or even the 30 its spec'd at. I used to remember
the values and color codes, now I have to look everything including
various formulas etc up. I have a heap of moonlights I want to make
for all our tanks all with wall warts of varous outputs.......At least
LEDS are cheap, as are resistors.....

A lot of the wall warts are form Coral life 3/4 and 1 watt moon
lights that went south. They are Luxeons, and were realy very nice and
bright, however they are totally enclosed in a plastic box, and have
no heat sinks of any kind on them, so they do not last long. So I have
a bunch of those wall warts to use as well, which are rated at 12VDC
and 350 ma but check out at 17.8 VDC......but those luxeons used
330/350 ma, but I can not very well afford to buy new luxeons any
more....especially at 8 or 10 bucks each as compared to 50 cents for a
super bright led in the 470 nm range, not when I am not experiienced
in electronics, it could get pretty costly for me pretty quick......
Regards


On Wed, 15 Feb 2006 16:36:31 -0600, "Pszemol" >
wrote:
>><>"Boomer" > wrote in message ...
>><>> "Are you interested in my comments ?"
>><>>
>><>> Yes
>><>>
>><>> Is your background electrical ? IDNR
>><>
>><>As I have clearly stated in my previous writing
)
>><>I am not an electrician I am electronic engineer.
>><>You know... transistors, microprocessors, resistors also software etc ;-)

--
\\\|///
( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....

[Pszemol]

"~Roy~" > wrote in message ...
> Right now I am trying to figure out what size resistor I need to drop
> the volts and such down on the varous wal warts I have. For example I
> have 7 brand new Nokia cell phone chargers....that are labeled as
> 350ma 3.7 volts. Online array wizzard shows a resistor of 1/4 w and
> 6.8 ohms is needed to be used with a 3.5 forward volt 30 ma LED....But
> when I hooked it all up th eled blew out after a short time.....I
> checked voltage on the wall wart and its actually putting out 7.9
> volts open circuit. So I am working on figuring out what size resistor
> I need to eat up the excess voltage and get me down to 3.5 volts and
> hopefully 20 or 25 ma or even the 30 its spec'd at. I used to remember
> the values and color codes, now I have to look everything including
> various formulas etc up. I have a heap of moonlights I want to make
> for all our tanks all with wall warts of varous outputs.......At least
> LEDS are cheap, as are resistors.....
>
> A lot of the wall warts are form Coral life 3/4 and 1 watt moon
> lights that went south. They are Luxeons, and were realy very nice and
> bright, however they are totally enclosed in a plastic box, and have
> no heat sinks of any kind on them, so they do not last long. So I have
> a bunch of those wall warts to use as well, which are rated at 12VDC
> and 350 ma but check out at 17.8 VDC......but those luxeons used
> 330/350 ma, but I can not very well afford to buy new luxeons any
> more....especially at 8 or 10 bucks each as compared to 50 cents for a
> super bright led in the 470 nm range, not when I am not experiienced
> in electronics, it could get pretty costly for me pretty quick......

What you need to know is that most of these wall warts like you call them
are unregulated power supplies. It means that they output variable voltage
depending on the load. Their rated voltage is only at rated load...
In your case: 3.7V would be there if it was loaded with 350mA but it is not.
Output voltage when the single LED is the only load will be very close to
the open circuit voltage - in your case 8V. It is because one LED is using
only 20mA, less than 10% of pwr supply rated. It happens I have also a nokia
phone and I checked open circuit voltage on mine - it is 9.7V. So as you
can see - this voltage will vary from unit to unit... Since you can measure
yours before you use it will be easy to you.

Next, you just need to use Ohm's law to calculate resistor value.
You take the supply voltage (8V) and substract LED voltage (3.5V)
and you will see that you will need a voltage drop of 8-3.5=4.5V on
the resistor... This voltage drop needs to be at 20mA current...
So the calculated resistance will be 4.5V/0.020A = 225 ohms.
The closest standard resistor values will be 200, 220 or 270 ohms.
Power dissipated on this resistor will need to be: 4.5V*0.020A=0.1W.
So you know the popular 1/8 W resistor will do just fine.

Since you deal with variable voltage source, you need to experiment
to select correct current for your LED. If your LED current is 30mA
or larger you will significanly lower life expectancy of your LED...

Also, if you want to connect more than one LED to a single power
supply link them in series with one resistor calculated for 20mA
and the voltage drop Vpwr - (Vled1 + Vled2 + ....). Same 1/8W.
If you need more than 2 LEDs you will run out of the voltage source.
Then you need to run them paralelly. Then each LED should have
its own current limiting resistor to eliminate possible differences
in working voltages of each LED causing them shine unequally.

Good luck!

[~Roy~]

Hey, thanks for jogging my memory....I got em all worked out and to
embed it further in my mind I worked out a heap of various
combinations both with the open circuit voltages and after droping
volts down to the warts rated voltage etc, then I bumped up what I
figured out against the online array wizzards etc and I did
good....Seems i can get by with mostly 100, 220 and 58 ohm resistors
for the most part unless I elect to drive a single LED with higher
voltage warts, then the 390 and 470 ohm 1 watt resistors woiuld be
needed, but that would be a waste of power source...

Should have my LED's tomorrow, so now I have something to work on over
the weekend, since its supposed to rain starting tomorrow and last
until Sunday evening or so.....SHould also have my shipment of goodies
from Big Als tomorrow as well so I should have lots to keep me busy.

I acquired a 30 gal Oceanic Cube that I am going to turn into a NANO
type tank. Plan on installing a back wall so pumps, heaters etc can be
installed in the back portion just like the JBJ Nano cubes.....Biggest
difference is the Oceanic tank is not going to be prone to cracking
like JBJ's nano cubes are....Probably make a hood out of acrylic and
use 3x 65 or so PC lights. I got a heap of good used electronic
ballasts from jewelery display cases when large chain store here
closed up....along with lots of bulbs, and there is a bunch that power
straight and square pin 96 watt quad bulbs as well..I was sort of
surprised quite a few of the bulbs are 50/50 and 10K .....guess they
made the diamonds etc show up better....

Once again thanks for the primer and refreshing my mind....NOw if I
can only see the colors on the resistors I'll be in good shape ;-)

Thanks

On Wed, 15 Feb 2006 19:16:15 -0600, "Pszemol" >
wrote:
snip What ROy had posted previously
>><>
>><>What you need to know is that most of these wall warts like you call them
>><>are unregulated power supplies. It means that they output variable voltage
>><>depending on the load. Their rated voltage is only at rated load...
>><>In your case: 3.7V would be there if it was loaded with 350mA but it is not.
>><>Output voltage when the single LED is the only load will be very close to
>><>the open circuit voltage - in your case 8V. It is because one LED is using
>><>only 20mA, less than 10% of pwr supply rated. It happens I have also a nokia
>><>phone and I checked open circuit voltage on mine - it is 9.7V. So as you
>><>can see - this voltage will vary from unit to unit... Since you can measure
>><>yours before you use it will be easy to you.
>><>
>><>Next, you just need to use Ohm's law to calculate resistor value.
>><>You take the supply voltage (8V) and substract LED voltage (3.5V)
>><>and you will see that you will need a voltage drop of 8-3.5=4.5V on
>><>the resistor... This voltage drop needs to be at 20mA current...
>><>So the calculated resistance will be 4.5V/0.020A = 225 ohms.
>><>The closest standard resistor values will be 200, 220 or 270 ohms.
>><>Power dissipated on this resistor will need to be: 4.5V*0.020A=0.1W.
>><>So you know the popular 1/8 W resistor will do just fine.
>><>
>><>Since you deal with variable voltage source, you need to experiment
>><>to select correct current for your LED. If your LED current is 30mA
>><>or larger you will significanly lower life expectancy of your LED...
>><>
>><>Also, if you want to connect more than one LED to a single power
>><>supply link them in series with one resistor calculated for 20mA
>><>and the voltage drop Vpwr - (Vled1 + Vled2 + ....). Same 1/8W.
>><>If you need more than 2 LEDs you will run out of the voltage source.
>><>Then you need to run them paralelly. Then each LED should have
>><>its own current limiting resistor to eliminate possible differences
>><>in working voltages of each LED causing them shine unequally.
>><>
>><>Good luck!

--
\\\|///
( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....

[Boomer]

"I am electronic engineer"

Yah Psz it sounded likey ou were one :-)

--
Boomer

If You See Me Running You Better Catch-Up

Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS

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"Pszemol" > wrote in message ...
: "Boomer" > wrote in message ...
: > "Are you interested in my comments ?"
: >
: > Yes
: >
: > Is your background electrical ? IDNR
:
: As I have clearly stated in my previous writing
: )
: I am not an electrician I am electronic engineer.
: You know... transistors, microprocessors, resistors also software etc ;-)

[Pszemol]

"Boomer" > wrote in message ...
> "I am electronic engineer"
>
> Yah Psz it sounded likey ou were one :-)

Yes, but it is far away from being an electrician.
These are two separate, quite different professions.

[AverageSchmuck]

I was and I guess unwillingly still an electrician. I have worked in
Industrial, Commercial, Residential both in maintenance and new
construction for a longtime. I have also done the high voltage side
commonly referred to as exterior electrician. Worked on voltages as
high as 14,400 VAC to as low as 2 VDC. I am not a person that can work
on electronic devices effectively but as a hobby sure. I can even go
as far as to say I have also worked as an electrician in both civilian
and military enviroments and I agree completely an electronic engineer
is not the same as an electrician by far. When I was active military
electrician I had to on a regular basis take the electrical engineers
out in field to get them familiar with equipment and point out errors
in their designs simply because they had a background in low voltage
DC circuits and didnt know what equipment was out their for anything
else. Example many of them to my surprise and never understood how
they dont know but seem to not know what a Double Throw 3 Phase switch
is and what it does. To me a simple thing but to them not so simple
till I show them one. Commonly used for facilities requiring 3 phase
AC power with a generator backup for power outages etc.

My question is why are people worried about electricution .. You have
bleed voltage on almost everything esspecially when electrical motors
are involved. As a motor is used it degrades both the copper windings
and the laminated steel core. which over time will cause some voltage
to either be conducted through insultaion into surrounding area.
Sometimes in transformers the area around is actually inducing voltage
off the windings and their is no actual insulation problem because
after all electricity is induced just like hot/cold etc. Back to the
bleeding issue it will say bleed into water which is not a huge risk
depending on voltage amount. General rule of thumb if you can feel it
fix it cause that would mean your getting votalge spikes higher than
20volts and could be a risk to your health but the fish probably not
they have no way of touching another phase and if they did you would
have a very sudden result because it would be a direct short and
wouldnt work at all.

Now that safety transforner that is suggested earlier. While in theory
it would work in actual field not so great. It is still transformer
and has same problems as any device that operates with windings and
induction etc. Now the real decision maker between grounding probe and
safety transformer. Put plain and simple the transformer is much more
expensive than grounding probe, harder to maintain, and after several
years will have to be replaced due to break down of winding and
laminated core. Best bet in my opinion stick with a ground probe. Its
simple, maintenance is easy basically wipe it down when you see build
up on it etc., and no learning curve. What I mean by learning curve is
a peice of equipment will cost you 10 fold more to use if you dont
understand how to use it and maintain it.

I hope that helps.

On Fri, 17 Feb 2006 10:56:24 -0600, "Pszemol" >
wrote:

>"Boomer" > wrote in message ...
>> "I am electronic engineer"
>>
>> Yah Psz it sounded likey ou were one :-)
>
>Yes, but it is far away from being an electrician.
>These are two separate, quite different professions.

[Pszemol]

"AverageSchmuck" > wrote in message ...
> I was and I guess unwillingly still an electrician. I have worked in
> Industrial, Commercial, Residential both in maintenance and new
> construction for a longtime. I have also done the high voltage side
> commonly referred to as exterior electrician. Worked on voltages as
> high as 14,400 VAC to as low as 2 VDC. I am not a person that can work
> on electronic devices effectively but as a hobby sure. I can even go
> as far as to say I have also worked as an electrician in both civilian
> and military enviroments and I agree completely an electronic engineer
> is not the same as an electrician by far. When I was active military
> electrician I had to on a regular basis take the electrical engineers
> out in field to get them familiar with equipment and point out errors
> in their designs simply because they had a background in low voltage
> DC circuits and didnt know what equipment was out their for anything
> else. Example many of them to my surprise and never understood how
> they dont know but seem to not know what a Double Throw 3 Phase switch
> is and what it does. To me a simple thing but to them not so simple
> till I show them one. Commonly used for facilities requiring 3 phase
> AC power with a generator backup for power outages etc.

Is it only my impression or you mix electric engineer with electronic engineer?

What I ment before is I am not electric engineer, I am electronic engineer :-)
These are, again, two different fields related to electrons and electric current...
The first guys is designing houses and factories AC wiring, calculates proper
circuit breakers and grounding wires or works on plans for building an power plant...
The second guy is designing electronic circuits like home audio-video equipment,
RF transmitters/receivers or industrial controllers including but not limiting
to microcontrollers and other silicon chips, keyboards, displays etc...
Two different things. Yes, electric engineer has to deal with high voltages and
high currents but same apply for electronic engineer - just an example: DC voltage
on the anode of screen tube of an ordinary CRT TV/monitor is in the range of 25 kV.
I understand electronic engineer works more with subtle components like silicon
chips, and currents rather in single mA than hundreds of Amps however I am quite
confused how can it be for any one of these two engineers to be not familiar with
a double throw switches... Cannot explain this in my mind.

But this is not the group for such discussions so we should rather end it quickly :-)

[AverageSchmuck]

You seem offended that was not my intention and if I did I apoligize I
was merely pointing some of my experience of field work and what I
have ran into. I dont understand why it is that way but it is for some
odd reason.

[Pszemol]

"AverageSchmuck" > wrote in message ...
> You seem offended that was not my intention and if I did I apoligize I
> was merely pointing some of my experience of field work and what I
> have ran into. I dont understand why it is that way but it is for some
> odd reason.

No, I am not offended at all :-) I was just trying to clear a confusion...
I was talking about an electronic engineer and you mentioned
electrical engineers - I hope everything is clear now :-)

[Boomer]

Yes, I know that. I know many in each field . They are all over the place where I work
:-) We also have a electrical engineer on our chem forum . He owns his own company and
designs laser equipment. You would call him a electronic engineer but he call himself an
electrical engineer. We have been toying with the idea and maybe a article on the future
reef lighting using, LED arrays.


"The second guy is designing electronic circuits like home audio-video equipment."

I use to know quite a few of these guys I'm an audiophile.

The terms are often used synonymously, although at times electrical engineering is
sometimes distinguished from electronics engineering, as you so stated :-)


--
Boomer

If You See Me Running You Better Catch-Up

Former US Army Bomb Technician (EOD)
Member; IABTI, NATEODA, WEODF, ISEE & IPS

Want to talk chemistry ? The Reef Chemistry Forum
http://www.reefcentral.com/vbulletin/index.php

Want to See More ! The Coral Realm
http://www.coralrealm.com



"Pszemol" > wrote in message ...
: "Boomer" > wrote in message ...
: > "I am electronic engineer"
: >
: > Yah Psz it sounded likey ou were one :-)
:
: Yes, but it is far away from being an electrician.
: These are two separate, quite different professions.