RE: Testing High voltage puck diodes.

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>

Leigh,

Thanks for the input. I happen to have a Simpson old style 5kv I think. I
bought it for my future old timer Tube coil for which I have all the stuff
... I trust my Beckman for diodes. I'll just pay attention to the forward
bias voltage then (and reverse shorts). I have to say I have seen some weird
transistor failures though.

Jim Mora

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Saturday, October 07, 2006 8:47 PM
To: tesla@xxxxxxxxxx
Subject: RE: Testing High voltage puck diodes.

Original poster: "Leigh Copp" <Leigh.Copp@xxxxxxxxxxx>

Hi Jim,

In the last 20 years I've heard a lot of talk about diodes (and other
devices) failing intermittently. I have yet however, to ever see a
semiconductor that was anything in between good, and bad <snip>

So for my 2.5 cents worth check them with a multimeter, and then install
them.

Cheers,

Leigh


	-----Original Message-----
	From: Tesla list [mailto:tesla@xxxxxxxxxx]
	Sent: Sat 07/10/2006 10:18 AM
	To: tesla@xxxxxxxxxx
	Cc:
	Subject: Testing High voltage puck diodes.
	
	

	Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
	
	Hello All,
	
	I am preparing to install 6 sets of six series connected HDB7.5 puck
	and stud diodes in a full wave 3 phase transformer oil tank (given
	there is room once the filament transformer is removed). These
diodes
	are rated at 7500 volts reverse each, with a forward current of 1.4
	amps. The recovery time is "standard". I called the engineering
	department and they said they should be fine without any balancing
	components at 60hz.
	
	Keeping in mind that these are take out surplus, I would like to
test
	them under somewhat hardened conditions, not just the forward
	junction drop. I was thinking of using half of one of my 15KV neon
	transformers across a diode test setup with say a 30 ma load of some
	sort. I have a 15kv dc probe around here somewhere which I will also
	test thoroughly!
	
	What would be the wisdom of noting the waveforms of each diode and
	discarding the ones that are inconsistent? Naturally I will test the
	diodes with a meter first. Anyone know a better or safer way to do
this?
	
	Thanks in Advance,
	
	Jim Mora
	
	There are a lot of bolts holding on the transformer/PS cover! And I
	would not like playing with these pucks once submerged!