6V / 9V / 12V Battery Charger with Constant-Current Charging

This is the circuit diagram of battery charger which has many important features such as current-constant charging, overcharge protection, short-circuit protection, deep discharge protection and more. The constant-current charging is a popular method for lead-acid and Ni-Cd batteries. In this circuit, the battery is charged with a constant current that is generally one-tenth (1/10) of… Read More »

Battery Charger + Small LED Lamp based Solar Cell / Photovoltaic

This is the circuit diagram of rechargable battery charger which use solar cell / photovoltaic as the DC source. This circuit works to charge 3 types of rechargable batteries that are lead acid, Ni-Cd and Li-ion. The lead-acid batteries are generally utilized in emergency lamps and UPS. The photovoltaic module or solar cell explained in… Read More »

Ding-Dong Door Bell

This ding-dong door bell circuit might become the simplest and cost-effective door bell circuit. The circuit is designed based on single IC 8021-2 which manufactured Formox Semiconductors. It is an 8-pin DIP (Dual Inline Package) IC whose only four pins, as shown in the above circuit design, have been used.

Simple Electronic Muscular Stimulator

Here’s a circuit which stimulates nerves of the part of your body exactly where electrodes are generally attached. It is useful to help remedy headache along with muscular discomfort and bring back frozen muscles that impair movement. Though it offers muscles stimulation and invigoration, it”s mostly an aid in removing cellulitis. The device comprises 2… Read More »

Solidstate Automatic Power-Off on Mains Failing

The following schematic diagram is the circuit of  solidstate automatic power-off on mains failing. A really good number of circuits which shut down the power to the load on mains failure have definitely currently shown up in EFY. This circuit is different compared to other similar circuits since it consumes no electrical power when the… Read More »