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 »

NiCd – NiMH Battery Charger

Here is the simple and low cost NiCd and NiMH battery charger circuit which can be used for various battery type and size. This battery charger use a regulator IC of LM317. Schematic diagram: The charge will start if a battery is connected between pins JP1-JP4 or JP2-JP4 or JP3-JP4. For example, if a battery… Read More »

Automatic Switching-on Emergency Light

Automatic Switching-on Emergency Light The schematic diagram shown right here is the automatic switching-on emergency light circuit which is controlled using IC. The most important capabilities of this circuit are: automatic switching-on of the light on main power failure and battery charger with overcharge protection. When mains electrical power is absent, relay RL2 is in… Read More »

5W Simple Inverter

Here’s a very simple circuit inverter that converts DC current into AC current, from 12V DC to 220V AC with output power of 5W max. Inverter circuit is typically used for emergency lighting, since the power output is small, which is about 5W only. But you can use this inverter for other purposes that do… Read More »