Thyratron heater supply?

[imix500]

Hi, I have a JAN 5849 that I'd like to light up for demonstration purposes. Can the filament of a large thyratron such as this be driven with DC? This tube has a reservior heater as well. Normally the two need to be feed with AC that is in phase. Can both be driven with DC? I'm asking because it's available. Thanks!

 

[Frank Berry]

Is it possible that this tube is a 5948 rather than a 5849?

If so, the tube has a 6.3 volt filament. It draws about 30 amps!
The reservior heater operates at 2.5 to 5.5 volts and draws about 5 amps.

Yes, you can operate these filaments from a d.c. supply.

 

[imix500]

Ah yes.

That's correct, it's a 5948. I knew that it needed around 30A for the filament, and I have an old lab power supply that can supply that. That's a lot of watts, but nothing compared to what it can switch!

 

[catrafter]

I've always just stuck a small colored lamp up inside the base and illuminated the 'tube' that way. Works great and with the right lamp, you can get that cool 'hydrogen blue' look!

 

[imix500]

That's a good idea. I've illuminated several that way as well, but this one is going to be firing for real into a 200 watt load. The tube won't even know it's there, but it should do fine to show ionization.

 

[Sch3mat1c]

Then hook 'er up and let it burn.

Hmm, 6.3V * 20A...I'll have to peek at the data sheet and see how jealous my C3J is...

Edit: can't find anything but 5949.

Tim

 

[imix500]

It's similar, and I'm still searching for the datasheet as well. I have enough info to fire it safely, but the exact specs are always nice to have. I think the 5948's peak pulse capacity is around 50Mw, just a little higher than the C3J.

 

[Sch3mat1c]

Well the 4959 says 25kV and 500A so 1.25MW... if it's anything like it, then yep! I'd expect more heater power given your estimate.

Would be nice to have a several kA hydrogen thy. for a quarter shrinker.

Tim

 

[imix500]

Indeed. Although I don't think other people in my building would appreciate the equivalent of a small EMP device, niether would anything with a silicon junction.