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 »
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 »
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 »