Battery Charger | Li-Ion Battery Charger Circuit Diagram

The National Semiconductors is manufacture LP2951 regulator.The choice of values is from an application note "Battery Charging", written by Chester Simpson. Diode D1 can be any diode from the 1N00x series, whichever is conveniently available. It functions as a blocking diode, to prevent a back flow of current from the battery into the LP2951 when the input voltage is disconnected. Charging current is about 100+mA, which is the internally-limited maximum current of the LP2951. For those wondering, this is compatible with just about any single-cell li-ion battery since li-ion can generally accept a charging current of up to about 1c (i.e. charging current in mA equivalent to their capacity in mAh, so a 1100mAh li-ion cell can be charged at up to 1100mA and so on)

5A DC Power Supply | High Power Adjustable DC Power Supply 1.25-25 V with 5A

The main component of the  power supply circuit is LM338K. The circuit 5A power supply with adjustable output voltage from 1.2 to 25V. Circuit is compact, you can see all of the elements except transformer, the printed circuit. Serial element to the cooling body mounted over the aluminum-angular Therefore, lies between the printed circuit boards and regulators LM338K, the other side is mounted on cooling the body with one flat surface.Also you can use a regulator with small fan, I have tested this circuit with computer power supply fan using as a cooling profile with mounting on the heat sink. Its work perfectly when it drive at more than 4.5 A.

500 W Inverter | 12V to 110V / 220V 500W Practical Inverter Circuit Diagram

By using this Inverter circuit you can convert the 12V dc in to the 220V Ac. In this circuit 4047 is use to generate the square wave of 50Hz and amplify the current and then amplify the voltage by using the step transformer.