15-08-2023, 07:31 PM
Here is a photo of the two 400Hz power supplies I've been repairing recently. The first had a leaked, but now quite dry, electrolytic capacitor and an open circuit mains switch. The other had a missing fuse and short circuit bridge rectifier together with a load of missing nuts and bolts where the PO had attempted something. That one has a wide frequency range from 45Hz to 10kHz with digital selection via rotary switch. I found an aviation frequency meter on ebay this week, now I have just the thing to test it with, unfortunately the calibration on the power supply is way off giving an output of 365 Hz when set to 400 and my frequency meter shows crazy values unless the voltage is heavily filtered before measurement although the waveform looks clean.
Both units are extremely heavy, the big one I had to carry upstairs one step at a time to get it into my office. I was surprised to see it had a 'swinging' choke input smoothing system - seems this is the way to go for a good power factor and less stress on the other components. learned something new there.
I've not been able to find any technical information on either unfortunately apart from a sales leaflet for the top one. Any information would be gratefully received, thanks. David.
Both units are extremely heavy, the big one I had to carry upstairs one step at a time to get it into my office. I was surprised to see it had a 'swinging' choke input smoothing system - seems this is the way to go for a good power factor and less stress on the other components. learned something new there.
I've not been able to find any technical information on either unfortunately apart from a sales leaflet for the top one. Any information would be gratefully received, thanks. David.
