I made the little test board with 2 lamps. the caps are .5ufd so I used 3. Looking good. |
One lamp has 12.7 volts. |
25.14 Volts across both lamps. |
A tip of the hat to thr DIT. It is a very useful circuit for someone who needs to reduce the voltage but has no transformer. The only draw back I see is being able to find the capacitor you need for a specific voltage / current requirement and you need to make sure the cap is rated for line voltage.
There is a ready supply of 50 volt caps but they will not work in this application.
The radio in the background has been in the dark for a long time. The pilot lamps were blown and I could not find replacements. That is not a problem any longer. I can put the 2 I'm testing in it.
Addendum:
The as built matches the circuit. One more thought. In the original we had a limiting resister. I am using the pilot lamp for the limiter. Using it with tubes the surge could be a problem without the limiter. The higher the current the more surge. A rule of thumb is inrush will be 8 to 10 times the run current. The inrush can last 15 - 20 seconds in a motor circuit. Just a little extra info.
From DIT.
ReplyDeleteThanks for your efforts, I will be able to use some of your points in the Class paper....