[GreenKeys] 1N4007s

[WA5CAB at cs.com]

I certainly agree that the selenium rectifier should be replaced before doing 
anything else.  Selenium rectifiers turned out to have a shelf life of only 
30-50 years typical.  But unless the one in this supply is a single diode (only 
two terminals on it), I wouldn't use the axial lead 1N4007 unless I really 
had to pinch pennies.  A much neater conversion is to use one of the square 
plastic bridge rectifiers.  Single hole mounting (under the original stack maybe) 
and hard terminals that take either solder or 1/4" spade disconnects.  If the 
original stack is only a full-wave rectifier (three terminals) you'll only use 
three of the four terminals on the block.  But the things are cheap.  I 
bought some surplus 35 amp rated units yesterday for only $3.50 each.  For this 
application, I would use one rated at least 400 PIV and 1 ampere.  I think the 
most common ones in surplus are probably going to be rated 1000 PIV and various 
currents.

In a message dated 1/24/2008 10:33:31 AM Central Standard Time, 
drhouse at dls.net writes: 
> John,
> 
> Can you explain or do you have a wiring diagram on how to do this?
> 
> I  do pretty well but my basic electronics training was 46 years ago.
> 
> Even educated guessing can be a bit dangerous when working in power  
> supplies.
> 
> Thanks,
> Don
> 
> 
> On 24 Jan 2008, at 8:00 AM, WB6BLV Central California wrote:
> 
> or replace the (health hazard) selenium with silicon (1N4007s are 3  
> cents
> apiece around here) and enjoy!

Robert & Susan Downs - Houston
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