6V DC to +15kV in portable backpack WW2 units ?

[lordvader88]

In the earliest WW2 infrared scopes like the German ZG 1229 Vampir 1229, and US models, some models would run off a big 6V battery in a backpack with electronics. And they would somehow make +15kV to power the 'light amplification tubes'.

So would they have been using vacuum tubes to make DC to AC, and then running a SMPS boost converter, like a flyback configuration/topology, and then stages of voltage doubling, before rectifying back to the 15kV DC ?

The whole thing might have weighed 30,40,50lb (14-22kg) iirc, either way 1 guy could carry it.

How were they doing it back then? And how many tubes would it take to make the switching actions, etc, to switch power tubes, like MOSFETs nowadays in SMPS

How did they do it in Vietnam era starlite scopes that also needed around 15kV (or maybe 10 or 20kV but u get the point)


I have played too much Wolfenstien type games. I want to use vacuum tubes and stuff to make super cool beam weapons and what not............but that never happened, instead they made early computers and RADAR

[Tac Eht Xilef]

I read a repair manual for the early US "sniperscopes" once. From memory, they used a straightforward electromechanical vibrator + transformer + rectifier valve/tube.

[chris_leyson]

Back in the 70's I bought a pair of surplus British army IR binoculars, think they were meant for tank drivers. Anyway they were about 500mm long and weighed quite a lot so they weren't intended for field use. Image intensifier tubes were CV143 or very similar but I couldn't get them to work, maybe I wasn't getting enough volts from my home brewed voltage multiplier. There is an interesting article from the virtual valve museum on the image converter tube construction http://www.tubecollector.org/documents/cv14x.htm and a link to a paper from 1947 which includes a schematic for a vibrator power supply http://www.tubecollector.org/docs/Infrared_converter_tube.pdf

[Circlotron]

Flyback converter of that vintage and voltage would have been similar to a car ignition coil, battery and a set of interrupter contacts with about 0.22uF across the contacts. Some kind of HV rectifier on the secondary side.

[mikeselectricstuff]

If they are using a vibrator, thay could potentially be using mechanical rectification, but a valve is probably most likely.

[Tac Eht Xilef]

Can't find any online copies of the manuals for the original "Sniperscope, Infrared, Set No. 1, (20,000 Volts)", but the basic arrangement is given in this technical report on "Image Forming Infrared" from 1946.

[tecman]

I have a IR sniperscope power supply I bought surplus as a teen.  It is 6v input.  As shown, it uses a vibrator to a transformer, and a vacuum tube rectifier.  Enclosure is about 2" x 4" x 6".  Still works.

paul