Low Cost Mosquito Repellent

Here is the simple and low cost mosquito repellent circuit design. The circuit serves to keep the mosquitoes out of the room or the location where the device is installed. According to certain publications, the frequency emitted by the male mosquitoes is said to be around 20—25 kHz, and so within the realm of ultrasound.… Read More »

6V and 12V Car Battery Charger

This 6V and 12V car battery charger circuit can be automatically charged, quickly and correctly, 6V and 12V batteries. Circuit design is divided into two series of modules that are: power supply module and the main charger module containing the regulator modules and direct current amplifier module.

DIY Electronic Cardlock Security System

Here is the DIY electronic cardlock security system that can be used as a lock to turn on dan turn off important electronic/electrical appliances. When card is inserted, depending upon the position of punched hole on the card, a particular appliance would be switched on. The card should be rectangular in shape with only one… Read More »

Smart Vibration Sensor Alarm

Here the circuit design of vibration sensor alarm. Initially, when power switch S1 is flipped to “on” position, power indicator LED1 lights up immediately. IC LM555 (IC1), wired as a simple latch circuit with control input, is powered and R-C components R4 and C5 connected at its reset pin 4 force the latch to standby… Read More »

Protector for Electronic Appliance with Three-Phase Power

This is the circuit design of the protector for electronic appliance with three-phase power supply. Many of electronic appliances need three-phase AC supply to work. If there is any failure of any of the phases, then it will make the appliance prone to erratic functioning and may even lead to failure. Hence it is of… Read More »

Glow Plug Control Module

This is the glow plug control module unit to raise the air temperature inside the engine cylinder for quick and reliable starting, to extend the battery life and reduce the diesel consumption. In diesel engines, the air in the cylinders is not hot enough to ignite the fuel under cold conditions. Therefore every cylinder of… Read More »

Bicycle Directional Lights

This is the electronic bicycle directional lights circuit that use inexpensive components and is a good substitute to many commercially available versions in the marketplace. This circuit works in an extremely different manner and is convenient to operate.

Simple and Low Cost Dew Sensor

This is a simple and low cost dew sensor circuit that can be used to switch off any gadget automatically in case of excessive humidity. Dew (condensed moisture) adversely affects the normal performance of sensitive electronic devices. The main part of this circuit is a low cost dew sensor element (resistor type). Although dew sensor… Read More »

3V Strobe Light Miniature

This is the circuit diagram of 3V strobe light miniature. The strobe lights are generally used to create nice looking visual effects in disco halls and auditoria. This post explain how to build the circuit of a battery operated portable miniature strobe light, using inexpensive components. For convenience and simplicity, an ordinary neon lamp is… Read More »