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.
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 »
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 »
This simple 220V light dimmer circuit can be used to adjust the brightness of mains lights. It also can be used to adjust the speed of AC motors. It uses a triac, diac and has a radio-frequency interference (RFI) noise suppression circuit built into it as well. Schematic diagram: Components List: R1 = 10K R2… Read More »
This is a 220V LED flasher circuit which is intended as a reliable replacement to thermally-activated switches used for Christmas tree lamp-flashing. This a low cost circuit and easy to built since it only use little amount of electronic components.. Schematic diagram: Component Parts: R1_________ 100K R2,R5______ 1K R3,R6______ 470R R4_________ 12K C1_________ 1000uF 25V… Read More »
The following scheme is a courtesy light circuit you can use to delay an electronic device to be disabled. For example, you can connect this circuit to the lamp in your room. When you turn off the lamp with a switch on the circuit, the lamp will remain lit in a certain period of time,… Read More »
Here is a simple and easy to build circuit diagram of a 12V car battery charger: Components List: R1 = 1Kohms D1 = 1N4001 T1 = 220V/17V 4A Transformer R2 = 1.2Kohms D2 = 6.8V 0.5W zener LD1 = Green LED R3 = 470 ohms TR1 = 4.7Kohms trimmer LD2 = Red LED R4 =… Read More »
This is a very simple FM receiver which build based on one transistor only. No chip or another active component. The output is connected to earphones, you need an amplifier circuit if you want to listen the radio with a loudspeaker.