Laptop / Notebook Protector

This is laptop / notebook protector circuit to protect your laptop or notebook or netbook from being stolen. Fixed in-side the laptop case, it will sound a loud alarm when someone tries to take the laptop. This highly sensitive circuit uses a homemade tilt switch to activate the alarm through tilting of the laptop case.… Read More »

Adjustable Symmetric 1 to 24VDC, 1A Power Supply

This is the circuit diagram of adjustable symmetric 1 to 24VDC, 1A Power Supply. This power supply give dual output positive and negatif output, you can adjust both positif and negative output (+1 to +24VDC and -1 to -24VDC). This kind of power supply also known as dual polarity power supply or splitted power supply… Read More »

Static Circuit Breaker / RFI Eliminator

This is the circuit diagram of Static Circuit Breaker.  Many a times you must have heard an undesired sharp sound emanating from the speaker, when any power appliance, like an electric iron, is switched ON of OFF. This problem is known as the Radio Frequency Interference (RFI). Some of the musical light, models, which employ… Read More »

Speaker Protection Circuit (Stereo)

This is the speaker protection circuit, provides stereo speaker protection and prevents switch-on clicks and DC components on the output of the amplifier connected.

Digital Tachometer / RPM Meter

This is the circuit diagram of Digital Tachometer / Digital RPM Meter which can be used for cars or motorcycles with 2 and 4 stroke petrol engines with any number of cylinders and contact breaker or electronic ignition systems. May be used as a general purpose revolution counter. Digital Tachometer Mainboard Scheme:

Digital DC Voltmeter based ICL7107 Chip

Here is the schematic diagram of digital DC voltmeter built based IC ICL7107. The power supply for this circuit is +5V. You may use 9V battery and then use regulator IC LM7805 to achieve 5V stabilized voltage. This circuit will be good to display your power supply output.

230V Automatic Night Lamp

This is the circuit diagram of 230V automatic night lamp based photo resistor to sensing the light environment. When the condition is dark enough, the one or more lamps will be turned on and when the condition is bright enough, then the lamps will be turned off.

Clap On / Off Switch

This is the circuit diagram of Clap On / Off Switch. The circuit allows you to operate your lighting or any circuit device which use 24V / 3A maximum supply, simply by clapping your hands. It has a relay output that can be used to turn external devices on/off.  This circuit is good and ideal for… Read More »

Traffic Baton with Bulb or LED Flasher

This is the traffic baton circuit which available in two versions that are traffic baton with LED flasher and traffic baton with bulb flasher. Both the circuits powered with a 6V, 4.5Ah rechargeable battery, which is clipped to the operator”s waistband. This circuit which come from EFY mag, will help the police or someone to… Read More »