Position: Index > Transmitter Circuit >

The principle of an FM transmitter

2016-04-03 08:13  
Declaration:We aim to transmit more information by carrying articles . We will delete it soon, if we are involved in the problems of article content ,copyright or other problems.

Next is an FM transmitter schematic presentation. Schematic showing below. In order to get a little tuning coil can put 4-40pF trimmer  capacitor  (optional) parallel in 1μH coil, L1. C1 / C4 and C5 / C6 is a ceramic capacitor, preferably fasting (low noise) type. C2 / C3 is electrolytic or can be tantalum types. Antenna is only a 12 "cable or a piano wire from 6" 12. "Before reading schematics, there are several points to note: 1, found that the signal receiver, ensure that there is a signal into the microphone, otherwise the circuit will not work. 2 , looking at the click of a microphone signal receiver position. 3, select more temperature stable capacitors to read a few of the schematic diagram will help you to better grasp the principle of this circuit is simple and very helpful.

Small FM Transmitter

R1,R3 = 100K
   R2 = 10K
   R4 = 470 ohm
C1,C4 = 470pF
C2,C3 = 4.7μF, 16V, electrolytic
C5,C6 = 4.7pF
   C7 = 4-40pF trimmer cap (optional, see text)
   L1 = 1μH
Q1,Q2 = 2N2222, NPN transistor
  Mic = Electret Microphone
   B1 = 9 Volt, Alkaline battery

 

VN:F [1.6.9_936]

 


Reprinted Url Of This Article:
http://circuits.radio-electronics.co/radio-rf-wireless/small-fm-transmitter/