Whelen Comander 5200 power supply

[Beemer63qc]

Hello, how can we tell if a power supply is toasted? When I put the power on it, there is a spark, but no life...
Also, the power supply is almost 40 y.o. and sold as new. Is it true that it sat on a shelf for several years, it is basically dead?
Thanks, Bernie, Montreal

 

[RS485]

Hi:
Quoting from page 45 in a Whelen manual:
"WARNING: Strobe light power supplies are meant to be used, not to
remain in an inactive state. Use them at all times, this will improve their
proper functioning. Any strobe light power supply that has been out of
service for a long period of time is subject to failure because the elec-
trolytic condenser loses the polarity formation. A strobe light power
supply not having been used for one year or longer is vulnerable to
failure, applies to 1993 & older units.
If this is the case, it is recommended to start operating the system on
a voltage that is reduced by 25 percent for 10 to 15 minutes before
putting the power supply into normal service. This will prevent over-
heating of the condenser while they reform. If the power supply, after
a long period of non use, is operated at full voltage immediately, there
is an excellent possibility that the condenser will become overheated."

I've encountered a few really old power supplies and have had some success reforming the caps. I've also had one or two where the caps were too far gone.

Here's what I've done: I run the power supply on the bench with a multi-meter measuring voltage on across the caps. I apply power for about 15 seconds and see how much voltage it measures and it my case, no more than about 125 at the start of the process (then it quickly drops down). I wait a few seconds and repeat this process and observe that gradually, the voltage will peak higher and higher. At some point, it will get to 270 or so and finally be enough to flash.

You can google "capacitor reforming" and probably find other methods but the above worked for me at least a couple of times.

What you really want to avoid is heat. If the caps become hot, back off. If you can't get the peak voltage to gradually increase, they may be too far gone (which means their likely leaking internally and generating too much heat as a result).

Hope this helps and good luck! Those old 5200s are really cool and very much worth saving!

 

[JohnMarcson]

Hello, how can we tell if a power supply is toasted? When I put the power on it, there is a spark, but no life...
Also, the power supply is almost 40 y.o. and sold as new. Is it true that it sat on a shelf for several years, it is basically dead?
Thanks, Bernie, Montreal

@RS485 (he posted at the same time as me ) is our Whelen power supply expert IMHO. He seems to know a lot more about the individual parts and pieces than I do, especially older supplies. We have a thread going about old Whelen power supplies that he offers a lot of good info in. I can help you with basic trouble shooting... but he will want to see pics the actual supply and go from there.

I have a few questions to start the troubleshooting;

• Did the bar ever work for you previously (I know it obviously worked at the time it was made)?
• If so what wire combo activated it?
• What wires are present? Red, Black, Purple, White?
• Does it have a power supply in one beacon and the other is a "dummy" or "slave" unit?
• Besides the speaker were there ever other options, i.e. directional strobes.

These are often an easy fix, there are a few components that fail which can be replaced by someone who knows what they are doing. Can you take the dome off the master side (and slave too if possible) and take a few pics? Can you get the power supply out and get some pics of the supply?

Even if this is "toast" all is not lost. The shell and crossbar are worth repairing and new "guts" are able to be found both accurate and more modern.

 

[Beemer63qc]

Hi:
Quoting from page 45 in a Whelen manual:
"WARNING: Strobe light power supplies are meant to be used, not to
remain in an inactive state. Use them at all times, this will improve their
proper functioning. Any strobe light power supply that has been out of
service for a long period of time is subject to failure because the elec-
trolytic condenser loses the polarity formation. A strobe light power
supply not having been used for one year or longer is vulnerable to
failure, applies to 1993 & older units.
If this is the case, it is recommended to start operating the system on
a voltage that is reduced by 25 percent for 10 to 15 minutes before
putting the power supply into normal service. This will prevent over-
heating of the condenser while they reform. If the power supply, after
a long period of non use, is operated at full voltage immediately, there
is an excellent possibility that the condenser will become overheated."

I've encountered a few really old power supplies and have had some success reforming the caps. I've also had one or two where the caps were too far gone.

Here's what I've done: I run the power supply on the bench with a multi-meter measuring voltage on across the caps. I apply power for about 15 seconds and see how much voltage it measures and it my case, no more than about 125 at the start of the process (then it quickly drops down). I wait a few seconds and repeat this process and observe that gradually, the voltage will peak higher and higher. At some point, it will get to 270 or so and finally be enough to flash.

You can google "capacitor reforming" and probably find other methods but the above worked for me at least a couple of times.

What you really want to avoid is heat. If the caps become hot, back off. If you can't get the peak voltage to gradually increase, they may be too far gone (which means their likely leaking internally and generating too much heat as a result).

Hope this helps and good luck! Those old 5200s are really cool and very much worth saving!

Thanks a lot for the info, really appreciated!!
I have followed your advice, done the step-by-step testing, nothing worked.
I even used caps from an old 1986 edge with the same specs on the Commander thinking that would do it, again, no life in the power supply. (The Edge power supply works well and is turned on regularly)
I have found a supplier that sells the same capacitors, for about 50$ each. So the question is, should I buy them or is it money out the window?
Thanks again for your time.
Bernie, Montreal, Canada

 

[RS485]

Thanks a lot for the info, really appreciated!!
I have followed your advice, done the step-by-step testing, nothing worked.
I even used caps from an old 1986 edge with the same specs on the Commander thinking that would do it, again, no life in the power supply. (The Edge power supply works well and is turned on regularly)
I have found a supplier that sells the same capacitors, for about 50$ each. So the question is, should I buy them or is it money out the window?
Thanks again for your time.
Bernie, Montreal, Canada

Hi Bernie -- doesn't sound like it's the caps. Your swap of known working caps proves that.
Next: Maybe look for cold solder joints.

Does it make any sound at all? Also, could you put up some high-res pics of both sides of the PCB? It always helps to see what we're looking at here. If you're comfortable with a multi-meter, I can suggest a few places to measure which might help guide our efforts.

EDIT: One more thing - most of the PCBs for these had reverse-polarity protection in the form of a diode and "littlefuse". Is there any chance your unit was subjected to reverse-polarity?