In sci.electronics.repair William Sommerwerck wrote:
"Cydrome Leader" wrote in message ...

That's pretty high tech for a product from the 1970s
to use a switching power supply.

My first color TV -- purchased in 1974 -- was a Sony KV-1920. It had a
switching supply.

that is pretty advanced.

I don't know which company was the first to make consumer products with
switching supplies -- but I wouldn't be surprised if it were Sony.

It could be.

the oldest thing in the junk pile with a switcher I have is an apple ][
computer.

Of course they forgot to add a cooling fan or ventilation slots which
Franklin Computer got right in their Ace series of clones.

I want to know more about this 1970s disco lighting system.