[ARC5] DC Power Supply

[Peter]

I just received two of the DC12V to DC24V 100V-250V 70W Converters.
Mounted on an old Dyna motor base and connected to a receiver it 
supplied the high voltage of 220Volt as adjusted. However the receiver 
protested with a high pitched noise in the audio output. Checking with a 
scope, there was a triangular wave of 200mV on the HV. This is the 
switching frequency of the converter of approximately 3Khz. The output 
of the transformer is rectified by one diode and filtered by a 10 
uF/450V capacitor.
I will try to add more filtering, maybe add a choke.
The output stay's constand over the input from 12 to 24 Volt and is 
adjustable from 100 to 250 Volt.

Peter KC0DGM