Re: Where to get high voltage diodes?

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Tesla729-at-cs-dot-com>

In a message dated 8/27/01 1:08:53 PM Central Daylight Time, tesla-at-pupman-dot-com 
writes: 


>
> This still leaves me without a rectifier and I could just guess around as to 
> what parts I need, or I could ask here and make sure I get tried and true 
> parts. (Remember the exploding MMC dabacle?) 
>
> I remember I need diodes in wheatstone config, but I think I am forgetting 
> something else. 
>
> The NST is a 12kv/60ma nst. Has anyone any suggestions on parts to get and 
> how many of these diodes to  put in series? I would guess I would want at 
> least 15kv of diodes to make sure I have some buffer, but I don't know about 
> current. Maybe I need several in parallel to distribute the current so as to 
> reduce over-heating. I just don't know and I don't want to guess around 
> because I think I would be doomed to guess poorly. 
>
> Thanks in advance. 
>



Garry, 

You may want to look into the rectifier assemblies from out of 
x-ray power transformers. These multiple-series diodes are al- 
ready soldered and affixed to a PCB and can usually withstand 
over 100 kV at several hundred milliamps. A man in Lousiana 
named Steve Flowers is always getting ahold of surplus x-ray 
power supplies and often sells these HV rectifiers assemblies 
on eBay. I think his opening bid is usually $19 for one of these 
units and they don't usually go up too high before closing. Of 
course, it would get a little more pricey if you were building a 
bridge rectifier (4 of 'em). I use a couple of these for a full-wave 
rectifier across the center tap ground and each hot end of two 
paralleled 15/30 NSTs for obtaining around 10 kVDC to charge 
my 100 uFD, 10 kV Maxwell energy discharge cap for my 
quarter shrinker/ coin crusher assembly, so they will work at 
voltages considerably lower than the x-ray transformer voltages 
and as a matter of fact, they would be under much lower stess 
than what they are designed for. 


Sparkin' in Memphis, 
David Rieben 

PS - Steve's email address is <Sflow26426-at-aol-dot-com> and 
he is a super guy to deal with. Mention my name and I'm 
sure he'll fix you right up :-)