UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

Mike. Watterson · 15th Mar 2019, 8:33 pm

Transformers though for 60Hz, if spec'd very tight, may be over-run at 50Hz as transformer power is related to frequency. Which is why SMPSUs (20kHz to 2MHz) were invented and the LOPT (10KHz or 15Khz approx instead of 50Hz) used for EHT instead of mains transformers.

The USA does use 220V approx for wired in major appliances and some maths indicates why USA doesn't have plug-in 2KW+ kettles or toasters like we do!

15th Mar 2019, 8:33 pm	#10
Mike. Watterson Heptode Join Date: Dec 2014 Location: Limerick, Ireland. Posts: 901	Re: 1939 KB 830 Receiver totally untouched. Transformers though for 60Hz, if spec'd very tight, may be over-run at 50Hz as transformer power is related to frequency. Which is why SMPSUs (20kHz to 2MHz) were invented and the LOPT (10KHz or 15Khz approx instead of 50Hz) used for EHT instead of mains transformers. The USA does use 220V approx for wired in major appliances and some maths indicates why USA doesn't have plug-in 2KW+ kettles or toasters like we do!