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Dont have 1n4004 diodes for Dummy load. Any alternatives ?






diachi

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As long as you know the voltage drop and current ratings of the diodes you can figure it out. Obviously signal diodes won't be able to handle that sort of current. Most silicon rectifier diodes should be fine though. You can always measure the drop with a DMM.
 

WizardG

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1N400x will work fine. All the 1N4000 series diodes have about the same forward drop. The difference between 1N4001 and 1N4004 is reverse voltage rating.
 
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1N400x will work fine. All the 1N4000 series diodes have about the same forward drop. The difference between 1N4001 and 1N4004 is reverse voltage rating.

^^^ yes, and I will add the 1N400x series are all 1 Amp.
 
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You may be able to salvage some suitable diodes from some
old circuit boards. The 1N400X series is a silicone rectifier
diode so look at the power input section of some PCBs. They
are also commonly used across relay coils to reduce back EMF.

Jerry
 

Benm

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The 400x series are indeed pretty much identical apart from maximum reverse voltage. I only keep 4007s in stock for that reason, they are (not interestingly) more expensive than other 1n400x diodes if you buy them by the 100 or so.

The 1n4004 is nothing special, it's rated to 400 volts dc so it's just a very common type of mains rectifier diode. It is normal silicon, high forward voltage, slow response, and can probably be substituted for -anything- you can yank out of a mains rectifing circuit that can handle 1 amp.

Considering how cheap they are i'd just buy them, but if you are in a hurry and have some discarded PC power supply around you can surely take some diodes from that as an instant substitute. Just make sure to pull them from the mains voltage end and not the output, as those diodes are often rated at a lower reverse voltage and could be lower drop, but faster, shottky ones as well.

In the application shown here that does not matter at all, but in general you should take not of this in higher voltage stuff.
 




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