Over the past few weeks, I have seen postings requesting schematics for
variable tube supplies. I finally took a few minutes to scan in a
couple from the GE Essential Characteristics Book from 1969, and
to convert a hand-drawn schematic to .pdf.

I doubt that these schematics are definitive, but I built two of them
and they work on my bench. The GE 1-compactron supply also exists as a
totally solid-state version as a dedicated BC-312 supply (MosFet as
pass element and a MPSA42 as the gain stage).

I put the schematics, along with a brief explanation, up on:

http://novatech-instr.com/Fun/ge_ps.pdf

I am pretty sure the last schematic violates the specs for a 12GB3, but
it seems to be working.

Comments are welcomed.

Steve.

--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

"Steven Swift" wrote in message
...
Over the past few weeks, I have seen postings requesting schematics for
variable tube supplies. I finally took a few minutes to scan in a
couple from the GE Essential Characteristics Book from 1969, and
to convert a hand-drawn schematic to .pdf.

I doubt that these schematics are definitive, but I built two of them
and they work on my bench. The GE 1-compactron supply also exists as a
totally solid-state version as a dedicated BC-312 supply (MosFet as
pass element and a MPSA42 as the gain stage).

I put the schematics, along with a brief explanation, up on:

http://novatech-instr.com/Fun/ge_ps.pdf

I am pretty sure the last schematic violates the specs for a 12GB3, but
it seems to be working.

Comments are welcomed.

Steve.

--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

Hello Steve,

Thanks for the interesting PS links. I'm not sure of their HT current
capabilities. I've been wanting to make a good bench HT, Fil, & Bias supply,
for a while now. I have a few ham radio PS that don't quite make it.. The
major drawback is that the Xfrs are only capable of 100ma. At times I could
use a little more that 400ma. Hopefully, someone reading this thread will
come up with a viable suggestion.

Cordially,
west

"west" writes:

Hello Steve,

Thanks for the interesting PS links. I'm not sure of their HT current
capabilities. I've been wanting to make a good bench HT, Fil, & Bias supply,
for a while now. I have a few ham radio PS that don't quite make it.. The
major drawback is that the Xfrs are only capable of 100ma. At times I could
use a little more that 400ma. Hopefully, someone reading this thread will
come up with a viable suggestion.

Cordially,
west

The best high current PS I have seen uses the same topology as the GE
1-compactron one but uses several 6080 (6AS7) in parallel. I have an
old transformer I am saving for that kind of thing that puts out
650Vct at 850mA. I have a TV transformer that is 550 at 250mA, but it is
being saved also. That's alot of iron.

The basic block will work for any load, just get enough current handling.

Good luck.

Steve.


--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

"west" writes:

Hello Steve,

Thanks for the interesting PS links. I'm not sure of their HT current
capabilities. I've been wanting to make a good bench HT, Fil, & Bias supply,
for a while now. I have a few ham radio PS that don't quite make it.. The
major drawback is that the Xfrs are only capable of 100ma. At times I could
use a little more that 400ma. Hopefully, someone reading this thread will
come up with a viable suggestion.

Cordially,
west

If you are willing to use transistors in your variable supply, along
with a fan and a big heatsink, it is quite easy to get 400mA up to
about 350V. For example, Hammond makes the 378CX, which is rated for
465mA of DC. You then use mosfets, which can easily handle the current
if you keep them cool. The B+ part of this schematic,

http://novatech-instr.com/PDF_files/ps_ss.pdf,

for example, is an exact copy of the GE 1-compactron PS, but done with
solid-state parts. Obviously, a lot of scaling needs to be done
(MPSA42 is only good to 300V). This particular one was done for 90v.

If you design it to cover 50-350 at 400mA, then you are going to burn
120watts worst case. That will require a fan, big heatsink and
several paralleled Fets, but it will work just fine.

I wasn't interested in spending that much on parts.

Steve
--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

In article ,
(Steven Swift) wrote:

The best high current PS I have seen uses the same topology as the GE
1-compactron one but uses several 6080 (6AS7) in parallel.

6080s are good for this. I used to have a regulated supply from an old
Ampex VR-1000 (2" reel-to-reel VTR) that delivered 250V at 6.5A.

I have an
old transformer I am saving for that kind of thing that puts out
650Vct at 850mA. I have a TV transformer that is 550 at 250mA, but it is
being saved also. That's alot of iron.

At the end of the day, the transformer is goung to be the biggest (and
certainly the heaviest and most expensive) single component.

Quality does not come cheap.

Chris.

For a single secondary transformer of considerable size it's often
cheaper to have the local transformer winder to do one as a one-off. I
have had transformers in the 1500 VA class wound for me cheaper than
Peter Dahl listed them as shelf stock. Winding your own is also
possible.

Many surplus sources exist if you scrounge around as well.

"Bret Ludwig" writes:

For a single secondary transformer of considerable size it's often
cheaper to have the local transformer winder to do one as a one-off. I
have had transformers in the 1500 VA class wound for me cheaper than
Peter Dahl listed them as shelf stock. Winding your own is also
possible.

Many surplus sources exist if you scrounge around as well.

For many years, I worked at John Fluke Mfg. which had a transformer
prototype model shop. For the 20 years I worked there, I never store
bought a transformer, instead using the prototype shop after hours.

At Novatech, I can wind small devices, but not the big iron stuff.

Steve.
--
Steven D. Swift, , http://www.novatech-instr.com
NOVATECH INSTRUMENTS, INC. P.O. Box 55997
206.301.8986, fax 206.363.4367 Seattle, Washington 98155 USA

Steven Swift wrote:

I wasn't interested in spending that much on parts.

Steve

And watch them go pop if something accidently shorts


Adam

"Adam Stouffer" wrote in message
news:5iAbf.5853$941.3990@trndny02...
Steven Swift wrote:

I wasn't interested in spending that much on parts.

Steve

And watch them go pop if something accidently shorts


Adam

It's surreal, ain't it?

Chris Suslowicz wrote:
In article ,
(Steven Swift) wrote:


At the end of the day, the transformer is goung to be the biggest (and
certainly the heaviest and most expensive) single component.

Quality does not come cheap.

Chris.


I would look at thrift stores like the Goodwill for an old colour TV
(tube type) and
salvage the power transformer out of it.