DougW

Jeff Strickland wrote:

> The lamp has continuity at something like 1.5mohms, which is pretty
> close to being open. I think I measure in at 1mohm.

That depends on the bulb and what temperature it's at.
Open is going to be infinite, but your basic 75W 120V blub
is about 60 Ohms cold. Halogen bulbs are a different aminal.

Just remember for any bulb it's best to keep your fingers off the
glass and use a clean cloth to handle them. Oil on the higher
output bulbs will cause them to fail early.

> I have several meters, the first one lied to me for whatever reason.
> My Fluke 77 says I have 21vAC on the secondary of the original
> transformer and the bulb is open until I get to the megohm range. (I
> think it might be the 20 megohm range to boot.)

I'd be thinking bulb or the wires leading to it.

--
DougW

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:WH47i.191025$jt2.40390@newsfe13.lga...
> Jeff Strickland wrote:
>
>> The lamp has continuity at something like 1.5mohms, which is pretty
>> close to being open. I think I measure in at 1mohm.
>
> That depends on the bulb and what temperature it's at.
> Open is going to be infinite, but your basic 75W 120V blub
> is about 60 Ohms cold. Halogen bulbs are a different aminal.
>
> Just remember for any bulb it's best to keep your fingers off the
> glass and use a clean cloth to handle them. Oil on the higher
> output bulbs will cause them to fail early.
>
>> I have several meters, the first one lied to me for whatever reason.
>> My Fluke 77 says I have 21vAC on the secondary of the original
>> transformer and the bulb is open until I get to the megohm range. (I
>> think it might be the 20 megohm range to boot.)
>
> I'd be thinking bulb or the wires leading to it.
>


Thanks. I'm stuck on the bulb too.

My meter told me the bulb was good, but now I am not sure about the meter.
Maybe the meter is okay, but the moron working the buttons leaves a bit to
be desired. In any case, the bulb is dead, and the original power supply is
putting out voltage.

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:WH47i.191025$jt2.40390@newsfe13.lga...
> Jeff Strickland wrote:
>
>> The lamp has continuity at something like 1.5mohms, which is pretty
>> close to being open. I think I measure in at 1mohm.
>
> That depends on the bulb and what temperature it's at.
> Open is going to be infinite, but your basic 75W 120V blub
> is about 60 Ohms cold. Halogen bulbs are a different aminal.
>
> Just remember for any bulb it's best to keep your fingers off the
> glass and use a clean cloth to handle them. Oil on the higher
> output bulbs will cause them to fail early.
>
>> I have several meters, the first one lied to me for whatever reason.
>> My Fluke 77 says I have 21vAC on the secondary of the original
>> transformer and the bulb is open until I get to the megohm range. (I
>> think it might be the 20 megohm range to boot.)
>
> I'd be thinking bulb or the wires leading to it.
>


Thanks. I'm stuck on the bulb too.

My meter told me the bulb was good, but now I am not sure about the meter.
Maybe the meter is okay, but the moron working the buttons leaves a bit to
be desired. In any case, the bulb is dead, and the original power supply is
putting out voltage.

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:WH47i.191025$jt2.40390@newsfe13.lga...
> Jeff Strickland wrote:
>
>> The lamp has continuity at something like 1.5mohms, which is pretty
>> close to being open. I think I measure in at 1mohm.
>
> That depends on the bulb and what temperature it's at.
> Open is going to be infinite, but your basic 75W 120V blub
> is about 60 Ohms cold. Halogen bulbs are a different aminal.
>
> Just remember for any bulb it's best to keep your fingers off the
> glass and use a clean cloth to handle them. Oil on the higher
> output bulbs will cause them to fail early.
>
>> I have several meters, the first one lied to me for whatever reason.
>> My Fluke 77 says I have 21vAC on the secondary of the original
>> transformer and the bulb is open until I get to the megohm range. (I
>> think it might be the 20 megohm range to boot.)
>
> I'd be thinking bulb or the wires leading to it.
>


Thanks. I'm stuck on the bulb too.

My meter told me the bulb was good, but now I am not sure about the meter.
Maybe the meter is okay, but the moron working the buttons leaves a bit to
be desired. In any case, the bulb is dead, and the original power supply is
putting out voltage.

Jeff Strickland

"DougW" <post.replies@invalid.address> wrote in message
news:WH47i.191025$jt2.40390@newsfe13.lga...
> Jeff Strickland wrote:
>
>> The lamp has continuity at something like 1.5mohms, which is pretty
>> close to being open. I think I measure in at 1mohm.
>
> That depends on the bulb and what temperature it's at.
> Open is going to be infinite, but your basic 75W 120V blub
> is about 60 Ohms cold. Halogen bulbs are a different aminal.
>
> Just remember for any bulb it's best to keep your fingers off the
> glass and use a clean cloth to handle them. Oil on the higher
> output bulbs will cause them to fail early.
>
>> I have several meters, the first one lied to me for whatever reason.
>> My Fluke 77 says I have 21vAC on the secondary of the original
>> transformer and the bulb is open until I get to the megohm range. (I
>> think it might be the 20 megohm range to boot.)
>
> I'd be thinking bulb or the wires leading to it.
>


Thanks. I'm stuck on the bulb too.

My meter told me the bulb was good, but now I am not sure about the meter.
Maybe the meter is okay, but the moron working the buttons leaves a bit to
be desired. In any case, the bulb is dead, and the original power supply is
putting out voltage.

doane_nut

Jeff,

250A (A=Amps) is ALOT of current, so much so that it can't be correct. You
probably have no more than a 250A service for your entire house. I think you
mean W (Watts), which is usually how bubs are rated; by the Voltage and
Watts. The amps required, based on Ohms Law, is the Watts divided by the
voltage. The bulb you have is 250W divided by 24 Volts = 10.42 Amps.

Sounds like the power supply you bought only puts out about 1.666A at 24V
(24V X 1.66A = 40VA). So, the power supply is too small. You need one rated
at 10A plus a few more Amps for a margin of safety, so at 24V output the VA
is 24V X 10A = 240VA minimum.

Howard


"Jeff Strickland" <crwlr@verizon.net> wrote in message
news:6R27i.2970$J76.2363@trndny03...
>I thought I knew this stuff, but there is a nuance that I'm not getting.
>
> I have a fiber optic lighting system in my swimming pool. It takes a
> 24v/250A light bulb. The bubl does not light, but the filiment is okay.
> The power supply (transformer) does not put out any voltage, so I bought a
> new one.
>
> The new transformer is stated to provide 40VA, but the light does not come
> on. My guess is that a VA and a "regular" A are different. What's the
> difference?
>
>
>
>
>
>
>

doane_nut

Jeff,

250A (A=Amps) is ALOT of current, so much so that it can't be correct. You
probably have no more than a 250A service for your entire house. I think you
mean W (Watts), which is usually how bubs are rated; by the Voltage and
Watts. The amps required, based on Ohms Law, is the Watts divided by the
voltage. The bulb you have is 250W divided by 24 Volts = 10.42 Amps.

Sounds like the power supply you bought only puts out about 1.666A at 24V
(24V X 1.66A = 40VA). So, the power supply is too small. You need one rated
at 10A plus a few more Amps for a margin of safety, so at 24V output the VA
is 24V X 10A = 240VA minimum.

Howard


"Jeff Strickland" <crwlr@verizon.net> wrote in message
news:6R27i.2970$J76.2363@trndny03...
>I thought I knew this stuff, but there is a nuance that I'm not getting.
>
> I have a fiber optic lighting system in my swimming pool. It takes a
> 24v/250A light bulb. The bubl does not light, but the filiment is okay.
> The power supply (transformer) does not put out any voltage, so I bought a
> new one.
>
> The new transformer is stated to provide 40VA, but the light does not come
> on. My guess is that a VA and a "regular" A are different. What's the
> difference?
>
>
>
>
>
>
>

doane_nut

Jeff,

250A (A=Amps) is ALOT of current, so much so that it can't be correct. You
probably have no more than a 250A service for your entire house. I think you
mean W (Watts), which is usually how bubs are rated; by the Voltage and
Watts. The amps required, based on Ohms Law, is the Watts divided by the
voltage. The bulb you have is 250W divided by 24 Volts = 10.42 Amps.

Sounds like the power supply you bought only puts out about 1.666A at 24V
(24V X 1.66A = 40VA). So, the power supply is too small. You need one rated
at 10A plus a few more Amps for a margin of safety, so at 24V output the VA
is 24V X 10A = 240VA minimum.

Howard


"Jeff Strickland" <crwlr@verizon.net> wrote in message
news:6R27i.2970$J76.2363@trndny03...
>I thought I knew this stuff, but there is a nuance that I'm not getting.
>
> I have a fiber optic lighting system in my swimming pool. It takes a
> 24v/250A light bulb. The bubl does not light, but the filiment is okay.
> The power supply (transformer) does not put out any voltage, so I bought a
> new one.
>
> The new transformer is stated to provide 40VA, but the light does not come
> on. My guess is that a VA and a "regular" A are different. What's the
> difference?
>
>
>
>
>
>
>

doane_nut

Jeff,

250A (A=Amps) is ALOT of current, so much so that it can't be correct. You
probably have no more than a 250A service for your entire house. I think you
mean W (Watts), which is usually how bubs are rated; by the Voltage and
Watts. The amps required, based on Ohms Law, is the Watts divided by the
voltage. The bulb you have is 250W divided by 24 Volts = 10.42 Amps.

Sounds like the power supply you bought only puts out about 1.666A at 24V
(24V X 1.66A = 40VA). So, the power supply is too small. You need one rated
at 10A plus a few more Amps for a margin of safety, so at 24V output the VA
is 24V X 10A = 240VA minimum.

Howard


"Jeff Strickland" <crwlr@verizon.net> wrote in message
news:6R27i.2970$J76.2363@trndny03...
>I thought I knew this stuff, but there is a nuance that I'm not getting.
>
> I have a fiber optic lighting system in my swimming pool. It takes a
> 24v/250A light bulb. The bubl does not light, but the filiment is okay.
> The power supply (transformer) does not put out any voltage, so I bought a
> new one.
>
> The new transformer is stated to provide 40VA, but the light does not come
> on. My guess is that a VA and a "regular" A are different. What's the
> difference?
>
>
>
>
>
>
>

Jeff Strickland

That's what I needed to know. the supply I bought is way too small.

And, the bulb is 250w not 250a. Sorry for that.




"doane_nut" <nospam@nospam.com> wrote in message
news:465ce1f2$0$4700$4c368faf@roadrunner.com...
> Jeff,
>
> 250A (A=Amps) is ALOT of current, so much so that it can't be correct. You
> probably have no more than a 250A service for your entire house. I think
> you mean W (Watts), which is usually how bubs are rated; by the Voltage
> and Watts. The amps required, based on Ohms Law, is the Watts divided by
> the voltage. The bulb you have is 250W divided by 24 Volts = 10.42 Amps.
>
> Sounds like the power supply you bought only puts out about 1.666A at 24V
> (24V X 1.66A = 40VA). So, the power supply is too small. You need one
> rated at 10A plus a few more Amps for a margin of safety, so at 24V output
> the VA is 24V X 10A = 240VA minimum.
>
> Howard
>
>
> "Jeff Strickland" <crwlr@verizon.net> wrote in message
> news:6R27i.2970$J76.2363@trndny03...
>>I thought I knew this stuff, but there is a nuance that I'm not getting.
>>
>> I have a fiber optic lighting system in my swimming pool. It takes a
>> 24v/250A light bulb. The bubl does not light, but the filiment is okay.
>> The power supply (transformer) does not put out any voltage, so I bought
>> a new one.
>>
>> The new transformer is stated to provide 40VA, but the light does not
>> come on. My guess is that a VA and a "regular" A are different. What's
>> the difference?
>>
>>
>>
>>
>>
>>
>>
>
>