13.8V 10A Regulator by 7812 , 2N3055

The power supply circuit is shown in Figures 1 and 2. A 7812 positive 3-terminal regulator is used for the main 13.8V 10A regulator, and this is followed by as many power emitter followers as needed for the current you require. The transistors are not critical. I used 2N3771 devices (50V, 20A, 200W) simply because I had a whole bunch of them in my junk-box. These are pretty much ideal, but I suggest that you use whatever you can get cheaply. If you use 2N3055s (as indicated in the schematic), expect to use four transistors for the first 10A, and one transistor for each additional 5A peak (or 4A continuous) output capability to ensure an adequate safety margin. The voltage rating is unimportant, as the main supply will only be about 22V with an 18V transformer.

As you can see, the regulator is made adjustable over a small range, and will typically give from 11V to 13.8V at full load. With the no-load voltage set to 13.8V (nominal 12V battery voltage), the output will fall to 13.5V at about 1.5A, and 12.8V at around 13A. This is fairly typical of the voltage drops that can be expected in a car installation. Needless to say, if the supply is designed for more current, then the regulation will remain about the same, but at the higher design currents.

Read More Source:
http://sound.westhost.com/project77.htm
Thank you.

Power Supply   Switching Power Supply   DC to DC Converter   Inverter
Battery charger   Led flasher   Motor speed controller   LM317   IC 741
RF radiofrequency   Electronic control   Digital Circuit   Alarm home system
DC to DC converter step up voltage   Mini project   Temperature control
FM receiver   Dual power supply   Fluorescent lamp   Pic microcontroller
Led display   RF amplifier   FM transmitter   LM324   LM723   TL494
2N3055   LM338   SG3525   Li-ion battery charger   Pulse generator