Low-cost 12V - 50W off-line switching power supply

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This is a simple low-cost 12 Volt 50W off-line switching power supply, which can be used for home projects or to learn operation of flyback converters. It can work over a universal AC line input range 90-264 VAC and provides a 12VDC output at more then 4A load. Line and load regulation is better then 0.5%. The unit has overcurrent, overtemperature and overvoltage protections as well as passive inrush current limiting. Output ripple are approximately 0.2 V. If you need to get lower ripple, you may put an additional output LC filter.

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About Power Supply
A power supply is a device that supplies electrical energy to one or more electric loads. The term of "power supply" is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy (e.g., mechanical, chemical, solar) to electrical energy.
A power supply may be implemented as a discrete, stand-alone device or as an integral device that is hardwired to its load. In the latter case, for example, low voltage DC power supplies are commonly integrated with their loads in devices such as computers and household electronics. More explanation about power supply can be found at wikipedia.org

This is the tutorial about "How to build an AC to DC power supply ". The video tutorial covers the basics of diodes, bridge rectifiers, and how to build simple unregulated AC to DC power supplies than can handle a few mA up to several Amps.

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The Holy Avenger said...

The toroid heats up to 87'C @ 1.1A / 12V load. The toroid I used was not the one recommended ( not available in my country). The Toroid specs were: ID = 0.6 inch, 2 were paralleled, color was yellow/ white, Lp=200uH, Rp=113mR, Gauge=SWG#22 (0.71mm), Secondary Wire gauge 0.75mm2, Aux = 0.125mm2 both were rubber insulated. Combined AL was 178nH/T2

Then I tried a different bigger core: ID=0.8 inch, 2 paralleled, color was green/blue, Gauge of pri was SWG#23(0.61mm2). Combined AL was 183 nH/T2