HV Diode Selection

dsavitsk · 29th June 2006, 05:46 AM

I am putting together a power supply that needs to give about 24mA at about 210V. I happen to have around a 125-0-125 transformer and an EZ81, so I thought I'd use these in conjunction with 2 silicon diodes to make a bridge rectifier. Does anyone have any suggestion of what to look for in terms of diodes to use. Digikey lists lots of D0-41 package ultra-fast diodes that are well over 800V. Does the choice matter beyond this? Any concerns with heat from this package? Anything else to concern myself with with a hybrid bridge?

DigitalJunkie · 29th June 2006, 06:30 AM

1N4007 (or UF4007) should be plenty beefy.
Of course you can shoot for a higher voltage,current,etc. if it pleases you.

SHiFTY · 29th June 2006, 12:14 PM

I had a couple of UF4007 go short circuit on me, so I never use them now.

Actually I had much better luck with plain old IN5408. 800V, 3A, what more do you need.

arnoldc · 29th June 2006, 03:08 PM

I use FR107 and have not had any failure, so far.

kevinkr · 29th June 2006, 04:16 PM

I've used UF4007 for quite a few years and never had one fail..
Given the rating of the EZ81 this or the 1N4007 ought to be good enough..

The soft turn off/fast recovery characteristic of the tube rectifier imho makes the use of fast silicon diodes unnecessary.

I'd say use whatever you can get at a reasonable cost with a PIV rating of at least 800V to allow for line transients.

I'm not convinced that I have ever heard a real difference between comparable diodes fast or otherwise. In terms of RF noise it definitely does make a difference that can be measured. RC snubbers incidentally can take care of this too, and are good practice for high voltage rectifier stacks regardless of diode type used...

Edits: still learning to spell I guess.. LOL

Tom Bavis · 29th June 2006, 07:20 PM

ONSemiconductor MUR4100E (1000V/4A) are rated for reverse avalanche energy - they will withstand huge overvoltage spikes. And I think they're .80 cents apiece...

pengboon · 10th September 2006, 08:34 AM

Quote:

Originally posted by Tom Bavis
ONSemiconductor MUR4100E (1000V/4A) are rated for reverse avalanche energy - they will withstand huge overvoltage spikes. And I think they're .80 cents apiece...

Has anyone used these with good results? I've just had a UF4007 failure and looking to use some better parts.

cheers!

29th June 2006, 05:46 AM	#1
dsavitsk diyAudio Member Join Date: Jan 2005 Location: Chicago	HV Diode Selection I am putting together a power supply that needs to give about 24mA at about 210V. I happen to have around a 125-0-125 transformer and an EZ81, so I thought I'd use these in conjunction with 2 silicon diodes to make a bridge rectifier. Does anyone have any suggestion of what to look for in terms of diodes to use. Digikey lists lots of D0-41 package ultra-fast diodes that are well over 800V. Does the choice matter beyond this? Any concerns with heat from this package? Anything else to concern myself with with a hybrid bridge?

29th June 2006, 04:16 PM	#5
kevinkr diyAudio Moderator Join Date: Sep 2004 Location: Boston, Massachusetts Blog Entries: 6	I've used UF4007 for quite a few years and never had one fail.. Given the rating of the EZ81 this or the 1N4007 ought to be good enough.. The soft turn off/fast recovery characteristic of the tube rectifier imho makes the use of fast silicon diodes unnecessary. I'd say use whatever you can get at a reasonable cost with a PIV rating of at least 800V to allow for line transients. I'm not convinced that I have ever heard a real difference between comparable diodes fast or otherwise. In terms of RF noise it definitely does make a difference that can be measured. RC snubbers incidentally can take care of this too, and are good practice for high voltage rectifier stacks regardless of diode type used... Edits: still learning to spell I guess.. LOL __________________ www.kta-hifi.net

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29th June 2006, 06:30 AM	#2
DigitalJunkie diyAudio Member Join Date: Apr 2003 Location: Portland,Oregon Blog Entries: 4	1N4007 (or UF4007) should be plenty beefy. Of course you can shoot for a higher voltage,current,etc. if it pleases you.

29th June 2006, 12:14 PM	#3
SHiFTY diyAudio Member Join Date: Jul 2002 Location: New Zealand	I had a couple of UF4007 go short circuit on me, so I never use them now. Actually I had much better luck with plain old IN5408. 800V, 3A, what more do you need.

29th June 2006, 03:08 PM	#4
arnoldc diyAudio Member Join Date: Apr 2003 Location: Makati	I use FR107 and have not had any failure, so far.

29th June 2006, 07:20 PM	#6
Tom Bavis diyAudio Member Join Date: Jun 2002 Location: Macedon NY	ONSemiconductor MUR4100E (1000V/4A) are rated for reverse avalanche energy - they will withstand huge overvoltage spikes. And I think they're .80 cents apiece...

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