2 x 10 Band Stereo Graphic Equaliser

The following diagram is the circuit diagram of 20 band stereo graphic equaliser which will controlling the audio signal in specific frequency range. The power supply used for this circuit is symmetrical (dual polarity) type, 15V DC.

Stereo VU Booster

This is a stereo VU booster circuit diagram based on transistor FCS9014 which usually used for pre-amp and regulator circuit and switching. With simple circuit design, this device could be built easily. Scheme diagram, bottom PCB layout and component placement provided on the following image: This circuit should be connected to audio channel before amplifier… Read More »

Tone Detector / Sound Activated Switch

The following circuit diagrams are tone detector circuit diagrams which also known as sound activated switch circuit. Actually, these circuits  use microntroller for switching because the circuits were designed for robot start up activation. But you can build switching module using relay. You may make a trial to use this circuit for other applications such… Read More »

Car Headlight Alarm

Here is the circuit diagram of car headlight alarm. This device can be set for one or two functions: First, to indicate that the head lights (or the side lights) should be switched off after switching off the ignition contact. With this circuit, there should be no dead battery due to headlights that were left… Read More »

Car Transistor Ignition

This transistor ignition circuit give your car to have better starting and smoother running, particularly at very high and very low RPM. Lower fuel consumption, less pollution, lower servicing costs. Drive economically, drive electronically. Only for petrol/gasoline engines. This circuit will reduce breaker point wear and provide cleaner spark. Circuit diagram: Wiring diagram with the… Read More »

Mini Voice Operated Relay

This is the circuit diagram of a voice operated relay. It similar with sound activation switch circuit which will turn on and turn off (connect and disconnect) the switch depending on the sound input. The output switch of this circuit is act by a relay. Components list: R1, R7 : 1K R2, R4, R8 :… Read More »

ATmega8535 Line Follower Robot

This is the circuit diagram of ATmega8535 Line Follower / Line Tracker robot. The circuit taken from the tutorial documentation. You may download the full tutorial at the end of this article. The ATmega8535 line follower robot uses 8 pieces of proximity sensor module. The sensor module use photodioda for detecting the reflection of light… Read More »

ATmega16 Line Follower Robot

Here the complete electrical circuit diagram of line follower robot which built based on ATmega16. There are three modules of line follower robot circuit that are sensor module, microcontroller module and DC motor module. IR sensor schematic diagram: The robot uses IR sensors to sense the line, an array of 8 IR LEDs (Tx) and… Read More »

Wireless Car Alarm

This circuit is a wireless car alarm system that is built using two circuit modules, namely modules of transmitter and receiver modules. This circuit works on FM radio waves. Car alarms can be used on vehicles that have a 6-12VDC power supply. You can use the voltage stabilizer if your car power supply is too… Read More »