FM Bug Transmitter Mint Box Circuit


Posted on Feb 5, 2014

Here is the circuit for the FM Bug. In total there are 18 core components that are needed for the fm transmitter to work properly. The far left side has the electret microphone and then things move electrically to the right until they hit the antenna. Don`t let this microphone fool you, it`s extremely sensitive albeit a bit clunky and big. You co


FM Bug Transmitter Mint Box Circuit
Click here to download the full size of the above Circuit.

uld shop around for a smaller microphone I`m sure but for this project, a standard electret microphone does the trick. The input is pulled high with a 22k resistor and passed to the amplifier circuit. The amplifier`s job in this circuit is to take the audio input and beef up the voltage/current so that when it gets transmitted it travels further. More amplification means more higher fm transmitting power and longer range. The last portion of the circuit with the 2nd BC547 is where the oscillator for the FM frequency is generated and mixed with the audio signal inorder to form the frequency modulation used for FM radio. Don`t worry, if all this is described a bit too quickly, the theory will be desribed more indepth in the next section.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    Remote Thermometer circuit
    -15 V 1-A Regulated Power Supply
    555 Fm Circuit Circuit
    Moduler Preamplifier
    Simple Police Siren US-Style
    Filament and Control Power Supplies
    mains operated led night lamp
    MS51C61 holiday lights ASIC circuit
    Barricade warning light flashing circuit
    Unsteady circuit diagram of a CMOS transistor pair



    Top