This is probably become the simplest radio frequency RF transmitter that you will find anywhere. It has a total of five parts and can be constructed into a very small space. It is great for science fair projects or other science related projects where short range transmission is useful.
It operates on 1.5 to 3 Volts, with small hearing aid batteries or lithium “coin” cells being ideal. A thermistor or photoresistor can be inserted in series with R1 to have a varying output frequency dependent on the input.
The frequency can also be changed by changing the value of C1. A 2N2222 transistor is recommended, but you can try other types also. Performance tends to vary from type to type as well as from transistor to transistor. L1 is 20 to 30 turns of thin magnet wire (24 to 32 ga.) close wound around a 1/8 to 1/4″ diameter non-conductive form. The coil is tapped 1/3 of the way from one end and the tap connected to the emitter of Q1. You may make experiment with all of the components value in this circuit. Nothing is critical in this circuit, but the performance can be varied considerably.
Simplest RF Transmitter Source: http://www.sentex.net/~mec1995/circ/rft1.htm
This is the circuit diagram of power amplifier 45W using power uPC 1230 as the…
The Horn Circuit This is a basic circuit of car horn and lamp flasher that…
This is the circuit diagram of drinking water alarm based a small water sensor by…
Here is the 200W MOSFET amplifier powered based on four piece of IRFP250N, they are…
This is the 300W RMS stereo power amplifier circuit project. This amplifier is based four…
This is an active stereo tone control circuit using very well known op-amp IC of…
View Comments
hi can h ask you that explian how does it work?
Can i use this RF transmitter circuit for a " toy radio control helicopter " to transmit signal.
Wil it work or not?
If your saying that it'll work then please send the circuit diagram for reciever part please.