Below circuit is an echo chamber circuit which can be used for smoothing your voice from the microphone. This circuit may used for any kind of audio signal (microphone, radio, mp3 player, etc). The echo chamber circuit is great for human voice (karaoke), i doesn’t needed for music sound. This circuit is quite complex with… 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 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.
This is 0-24VDC digital PIC power supply circuit. This variable power supply controlled with PIC microcontroller. There is LCD display in this circuit which will show the actual value of power supply output. This power supply use push on switch to adjust the output voltage and current value. Schematic Diagram: Component List: C1 = 2000uF… Read More »
Here is the AM Radio receiver circuit diagram based on old single IC MK484. Components List: R9, R10_________ 6R8 R6_____________ 100R R3_____________ 1K R1_____________ 4K7 R7_____________ 5K6 R4_____________ 10K R2_____________ 100K R5_____________ 150K R8_____________ 820K Pot_____________ 10K log pot Coil & ferrite bar set C7______________ 470p ceramic C, C4, C5, C6_____ 470nF monoblock C2______________ 100nF… Read More »
This circuit is a powerful three stage, 9V FM transmitter (Tx) with a range of up to 1 kilometer in the open. It uses an RF transistor in its output stage and two BC547″s for the first two stages. Distance of trans-mission is critically dependent on the operating Conditions (in a building or out on… Read More »
This a two station intercom. It uses two wires to run between each intercom unit. Each is self contained with its own battery, speaker, microphone and amplifier circuit. An LM386 audio power amplifier is used. It is widely available, used a minimum of external parts and is well suited to battery operation. It will give… Read More »