I have listed some suitable sources of HV rectifier modules, epoxied, so
that you don't have to wire the diodes in series yourself and mount them.
These are industrial quality, what the broadcast and high power RF
manufacturers typically use. When needing 10-20 kV plate supplies, they
move toward air or oil-cooled stacks, in insulated rails or plates. Those
are quite beyond what you might want for an amateur amplifier ( I only
assume this!). Then there are the sources in the ads in the back of QST. I
don't vouch for these, as I have never used them in anything, but the same
principles apply. I would expect that any reputable manufacturer of diode
stacks for HV would have real ratings based on at least some testing to
make sure they don't errupt in flames when energized. For the companies
below, some do offer small quantity buys using a credit card, or at least
they have distributors who can sell them such as Newark, Avnet, Harrison,
etc.
The epoxied modules should be mounted on a flat smooth heat dissipating
surface if you are planning to push the average current, and use
silicone-based heat transfer grease. The foward V drop x the current gives
you how much power you will have to dissipate in heat load in your power
supply. Most have forward voltages of 5-20 volts, depending on # of
individual diodes inside. When checking diodes like these with a Ohmeter,
the battery inside is too low in voltage to turn on the stacks. I use a 24
Volt power supply, variable, with current limiting or a resistor in series
to keep the max I under the diode average rating, to test the forward
direction. Reverse testing should be done with a small high potter or high
voltage supply of limited current (< mA). Most of the diodes below are also
available in >5 kV PRV, I only listed the common part #.
Electronic Devices, Inc. Yonkers, NY (914) 965-4400
KVF 5 5 kV PRV, 0.5 Amp avg, 50 Amp surge (8.3 ms) - this is a leaded
block, about an inch long
KVP 5 5 kV PRV, 1 Amp avg, 50 Amp surge - this is a block with solder
turrets
KMO 5 5 kV PRV. 1 Amp avg. 50 Amp surge - this is a block with turrets
All are available in longer sticks, with higher PRV, also in fast recovery
diodes (not needed for 60 Hz mains power supplies, but useful for snubbers
for inverters, high freq switcher recitifiers, etc.)
Semtech Corp., Newbury Park, CA (805) 498-2111
SCH5000 5 kV PRV, 0.5 Amp avg, 50 Amp surge - leaded block about 1.14
inches long, 2 diodes in half wave assembly
SCHS5000 5 kV PRV, 2 Amp avg, 80 Amp surge - leaded block about 2.5
inches long
SHVM5 5 kV PRV, 0.5 Amp avg, 20 Amp surge - stud mount button, about 2
inches diameter, an inch tall
S2HVM5 same, except 2 Amp avg, 50 Amp surge - same package
Varo Quality Semiconductor Inc., Garland, TX phone # unknown
H441 6 kV PRV, 0.65 Amp avg, 20 Amp surge - complete full wave
bridge in a 2 inch square module
VC40 4 kV PRV, 2 Amp avg, 35 Amp surge - 3 inch long block, faston
connector blades
I am not sure Varo is still around, but I have used these things years ago,
the bridge is very nice
HV Component Associates, Inc., Wall, NJ, (908) 938-4499
1HV5K 5 kV PRV, 1 Amp avg, 50 Amp surge - 2.5 inch long block with
solder turrets
3HV5K same but with 3 Amp avg, 150 Amp surge, 4 inches long
HV5 5 kV PRV, 1 Amp avg, 50 Amp surge - similar to the Varo
VC40 in appearance
3HC5 same but in 3 Amp avg, 150 Amp surge
HVCA offers a very broad selection, with multiple diodes (half wave)
assemblies, RC compensated, higher PRV, and leaded single sticks similar to
the EDI KVF series and others
Semikron International, Nurnberg, Germany, 09 11-65591, USA phone # (603)
883-8102
HSK E 5000/2200-0.25 5 kV PRV, 0.35 Amp avg, 60 Amp surge - leaded stick
about 3 inches long
HSK E 5000/2200-0.5 same but 0.6 Amp avg
HSK E 5000/2200-1.2 1.45 Amp avg
SKV 1/2 B 6000/5400-0.5 6 kV PRV, 0.45 Amp avg, - half wave assembly, 2
series stacks,
information provided by.....
john
K5PRO
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