DIY mains powered power supply

[boylesg]

This might be pretty trivial stuff for most of you guys but it is my first successful attempt at this sort of thing and it worked first time so I am pretty chuffed about it.

The transformer was from a salvaged from discarded guitar amplifier I think it was. It had two secondary windings, one center tapped and one not.
Tested it out with a 24VAC wall plug and then calculated the windings from inductance measurements and my calculations gave me output voltages with 250VAC were pretty close to the mark. As it turns out the non center tapped winding gives me 12VAC while the center tapped winding gives me 18VAC/36VAC. Connectors for these are on the left side of the lid.

I then connected these to basic bridge rectifier circuits using salvaged bridge rectifiers from TV circuit boards. That gives me -18VDC, GND, +18VDC / GND, 36VDC from the non-center tapped winding and -23.5V, GND, 23.5VDC / GND, 47V from the center tapped winding. The connectors for these are on the right side of the lid.

More convenient than using lantern batteries to test my tesla coil circuitry etc.

 

[BradtheRad]

Very positive. Salvaging parts from equipment is a time-honored technique.

I believe I remember disassembling a tv set in my youth, before I even knew how to make anything with the components I extracted.

 

[boylesg]

Very positive. Salvaging parts from equipment is a time-honored technique.

I believe I remember disassembling a tv set in my youth, before I even knew how to make anything with the components I extracted.

I can't bring myself to pass a discarded TV by these days without cracking it open to see if there is anything useful inside it.

Starting to notice the first LCD tvs being discarded, at present it is mosty the cathode ray ones. But the LCD tvs contain useful shcottky rectiers and MOSFETS.

Scored a flyback transformer from an ancient black and white tv yesterday, i.e. the ones that don't have rectified HV output.