12V 50W AC-DC Power Supply
This is a simple low-cost 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. Link
Other Link
bench variable power supply 0-30V
DC Power Supply 9 volt using TIP31 transistor
High voltage spill equal DC 900V
High Voltage mini power supply by 2N2222

