I have a power supply to a telephone system module that has a 1n504 diode. The diode gets very hot and sometimes burns up. The circuit board gets discolored around this diode. Anyone know the specs on this diode and is there a diode I can replace it with that would work better? Would a 1n4001 work in place of it? Thanks for your help!

 

No because 1N4001 is rated for 50V only. You need 100V or higher.

You can use any of 1N4002, 1N4003...1N4007 to replace it. But there will not be any improvement to the heat problem because it is load current related.

You can try to leave as long as possible the leads on the diode to ease the problem a little.

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L.Chung

 

Alright, I will go buy a 1n4003 and try that out. Thanks for taking the time to help me out.

 

In addition to LChung's good advice on longer leads, you can solder small copper fins (best) or clamp small aluminum fins to the diode leads as close to the diode body as possible. Bigger is better within space limitations.

awright

 

Wouldn't it be best to replace it with something like this, if it'll fit on the board of course:

http://www.rapidelectronics.co.uk/rk...6256&XPAGENO=1

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Angry!? I'm absolutely electrolytic!

Will have to make do with myspace now I guess...

 

I think you may mean a 1N5404 diode. The 1N540X series diodes are 3A where as the 1N400X are rated at 1A. The 1N540X series are about 1/4" diameter whereas the 1N400X are about 1/8" diameter. The physical size determines the current rating. It would be a very bad idea to replace the larger size with the smaller size.
As mentioned earlier, a heatsink my be necessary.

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The great thing about electronics is unlimited ways to do the job. The only limit is one\'s imagination. I generally think my way is best.
Show me a different way. I have an open mind.

 

I think that this diode is trying to tell you somethind.

Your problem is probobly a short somewhere else in the circuit. Start smelling for overheating somewhere else in the circuit.

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76 years and still learning.

 

Smelling??
I use my finger to do the smelling. :lol:

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Uncle $crooge

 

MMMMMM and we thought the Tasmanians were strange :shock:

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" The only way to avoid human error is to avoid the use of humans"

 

I bet you have never seen blacken PCB areas around diodes and zeners connections caused by overheating.

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L.Chung

 

Most commercial pcb's are made from compressed paper. Sure it blackens when a power device is near it for years. Your finger would probably blacken too.
Tasmania is in Oz, isn't it? People down under are upside down so probably use their toes to do the sniffing. :lol:

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Uncle $crooge

 

I use my fingers too :lol:

If I smelled my circuit for hours, then I feel that I have turned into a dog! :lol: :shock:

But smelling is ineffective, until you see smoke! and trust me, the smell is not good. So go spray some air freshner on your circuit, and maybe the smoke will push up the air freshner smell. :lol:
BUT, if your circuit is precious, ignore putting air freshner on it.

It is better to use your finger, because it detects heat before the smoke arrives. In fact, my finger prevented parts from smoking, because when my finger starts to get hot, I immediately disconnect the power.

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-=: The best low-priced components to troubleshoot with are the speaker and the LED :=-

 

A 1N504 330mA RECTIFIER DIODE IS HARDLY A PPOWER DEVICE!

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76 years and still learning.