FM adaptor circuit for car stereo

With this compact FM adapter schema plugged into the audio out of your cassete player or i Pod out put,you can listen your favorite music on your car stereo.This schema is very useful if your car stereo does not have an auxiliary in socket.The schema is nothing buy an short range FM transmitter.





The FM transmitter schema is based on low power NPN transistor 2N2222.The tank schema consisting of L1 & C1 produces the necessary oscillations at the collector of Q1.The capacitance C4 , resistance R3 & R4 performs the function of mixing the stereo out put from the audio player or i-Pod.The emitter resistance R2 provides sufficient stability to the schema.It also limits the collector current to increase the battery life.



Notes.

* Use a 28SWG , 10 cm insulated copper wire as antenna.
* For L1.make 8 turns of 20 SWG insulated copper wire on a 5mm dia plastic former.
* Power the schema from a 3V battery.
* Assemble the schema on a good quality PCB or common board.
* C1 can be a 50pF trimmer.