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 »

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 »

Home Telephone Call Recorder

This is the circuit connection of home telephone call recorder that uses very few components. In order to understand its working, we must first have the basic knowledge of standard telephone wiring and a stereo plug. In some countries, landline telephones primarily use RJ11 wiring, which has two wires—tip and ring. While tip is the… Read More »

12W Audio Amplifier based MOSFET 2SK135 / 2SJ50

This is a small 12W audio amplifier over a load of 8 Ω, that combining the NE5534 integrated with a pair of V-MOSFET transistor output stage technology as we get excellent sound performance. MOSFET 2SK135 / 2SJ50 from Hitachi is used in this circuit. Input sensitivity of the circuit is 3V RMS maximum, the distortion factor… Read More »


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