This is the best circuit of an FM transmitter to broadcast your “voice or music” around the place. There are numerous circuits of FM transmitters on the web however some are large circuits containing lots of curls and segments, some drain battery very quick, some are low power yet do not perform well and the range is exceptionally short. This circuit isn’t just long-run when contrasted with other “Transistor FM transmitters” yet additionally truly steady and energy saver.
Numerous FM transmitter circuits utilize two transistors for expanding the amplifier signals to hear feeble sound signals yet the beneficial thing about this circuit is that it utilizes just a single transistor. The microphone is very sensitive to hearing.
Hardware Components
The following components are required to make FM Transmitter Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Antenna | 12 inch | 1 |
| 2. | Resistor | 39K, 1K, 100Ω | 1, 1, 1 |
| 3. | Coil | 2turns of #24 wire | 1 |
| 4. | Mic | – | 1 |
| 5. | Transistor | 2N3904 | 1 |
| 6. | Trimmer capacitor | 1-30 pF | 1 |
| 7. | Capacitor | 1nF, 28pF, 5pF, 62pF, 10nF, 0.47µF, 3pF | 1, 1, 1, 1, 1, 1, 1 |
| 8. | Variable Resistor | 1-10 K | 1 |
2N3904 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of 2N3904
FM Transmitter Circuit
Circuit Operation
The circuit intends to take “low power” from the battery and broadcast a strong signal on the FM band from 103 MHz to 108 MHz however you can change frequency width by making a few examinations with the coil. For antenna use, any wire of 20 to 30 centimeters, for expanding range additionally fit the circuit in a metal box and utilize 80 centimeters wire as an antenna and don’t wound the wire of antenna keep it vertical, keep the leads of the parts short and weld them as close as conceivable on PCB. The variable resistor of 1 – 10 K close to the amplifier is to change the microphone’s voice quality, change the variable resistor to any value where you get the best quality, and utilize a fixed resistor of that value in the spot of the variable resistor.
On the other hand, if you need to utilize fix resistor in the spot of the variable resistor and would prefer not to change the sound quality at that point utilize a 5K resistor. On the off chance that you need to make the microphone progressively delicate, at that point expel the 1K resistor close to the microphone. If you don’t need a sensitive microphone and need to utilize a microphone from close to that point change the estimation of 1K resistor to 10K.
Applications and Uses
The FM transmitters are used for playing sound gadgets on
- Vehicles
- Computer
- Television
