The Stovebolt Site Forums The Shop Area The Electrical Bay The Radio Bench Vibrator (chopper) max current?

Anyone happen to know what the maximum current is for the vibrator, or as I call it a chopper, in the front end of tube radios? It’s been awhile since I messed with one. I plan to build a converter the old school way from spare parts and duct tape. Thanks

What year truck?

Maybe something here might help you?

hi,
I don't have any datasheets for those vibrators, but here is my 2 cent reasoning...

In one of my trucks (50 1 ton) the factory radio is using an original type vibrator, likely an Aerovox A-100 or Cornell-Dublier C-00 or Radiart 5300, i forget which, but those should be interchangeable parts.
The radio draws about 4 - 5 amps at 6.3V, about 1.6 of those amps is going into tube heaters, that leaves about 2.4 - 3.4 amps into the vibrator.
The vibrator was a common failure mode in the radio, it could be a little as months to needing a new one, but usually measured in a few years.
If you want your design to last similar to the radio service life of the 1950s i would stick to the conservative limit of 2-3 amps through the vibrator (4-5 amps at start up for 30 seconds while tubes warm up is fine).

But... if your design is easy to get to (for replacement purposes) and you put a big heat sink or fan on it you could probably push it to 2x or 3x from what my radio gets out of them.
My immediate concern would be self heating under load, if you want to push your luck, put a temperature probe on it and make sure you are comfortable with the results.
-s

We used to open up the sealed can on a vibrator and dress up the points when they got funky and the thing quit buzzing. That's probably the limiting factor- - - -whatever current the points can handle without burning. They're probably not as rugged as distributor points, as I remember them being about half the size of ignition points, and ignition points get toasty at about 5 amps. I'd guesstimate a vibrator might handle 2 1/2 - 3 amps maximum, probably less if you want to have long term survival. A vibrator's original purpose was to create a DC square wave which could be transformed like AC up to a much higher voltage for use with vacuum tubes. That process didn't involve much current across the points.
Jerry