Category Archives: Power Electronics



100W Inverter 12VDC to 220VAC

The following diagram is an inverter circuit which will give you 220V AC 50Hz with maximum power output of 100W. This inverter built using transistors for both the square wave generator module and the amplifier module. Inverter Diagram: The Q1 and Q2 used generate square wave. Q5-Q8 amplify the signal and the transformer to increase… Read More »

Solid State Relay

This is the circuit diagram of solid state relay. In reality, it is not a relay after all. There’s no ‘relay’ found, just the electronics circuit which does the switching. It operates a similar way as a relay; it is possible to use a low voltage to switch a higher voltage or better than ordinary… Read More »

12V Lead-Acid Battery Monitor

This easy circuit makes it possible to monitor the charging process to a higher level. Final adjustsments are simple and easy and the only device required is a digital voltmeter for the important accuracy and reliability. Connect an input voltage of 12.65 volt between the positive and negative poles and adjust the 10K trimmer potentiometer until Led 10 lights up.

Automatic 9V Battery Charger

This is the scheme diagram of automatic 9V battery charger circuit, the parts list provided below the schematic image. The circuit was designed by Jan Hamer, translated by Tony Van Roon dan republished in this circuit diagram site. The circuit details are based on european standards: 120E, 150E, etc. The ‘E’ just stands for Ohms… Read More »

6V Gel Cell Battery Charger

The following scheme diagram is the battery charger circuit for 6V Gel Cell battery type only. Components List: R1 = 22 ohm, 1W R2 = 270 ohm R3 = 220 ohm *R4 = 715 ohm, 1% *R5 = 3.57K, 1% *R6 = 1.40K, 1% *R7 = 1.47K, 1% C1 = 0.1uF, ceramic C2 = 0.1uF,… Read More »

NiCAD Battery Charger with Current and Voltage Limiting

The following diagram is the schematic diagram of Ni-CAD battery charger circuit which featured with current and voltage limiting to keep the battery lifetime. The lamp L1 will be light brightly and the LED will be out when the battery is low and battery charging in progress, but the LED is very bright and the… Read More »

Lead-Acid Battery Charger

The following scheme diagram is the circuit diagram of Lead-Acid battery charger. This circuit provides an initial voltage of 2.5 V per cell at 25 ℃ to quickly charge the battery. The charging current decreases as the battery is charging, and when the current drops to 180 mA, the charging circuit reduces the output voltage… Read More »