Photocopier Transformer 5000V 300mA

Fessenden, Sun Apr 16 2017, 04:46PM

Anyone have experience with these? Available from herbach and rademan back in the late 90s. Supposedly they need a cap connected to a secondary winding to get full output voltage. Ferroresonant?

Did some quick measurements on one. With 12V on the primary got 280V on the HV secondary with no cap connected. 3 wires are on the resonant secondary. Got 15V and 75V between those wires. Connecting a 15uF cap to the 15V wires made the HV winding jump to 350V. Connecting to the 75V wires made the HV winding jump to 500V+.

Found this. Seems to describe the same transformer:



What rating cap is needed for this transformer and which of those 3 wires should be used?