Transmitter and Receiver Infra Red Headphone

Transmitter and receiver circuit using infra red audio signal is applied to emit an audio signal and will received on a headphones. Making his series is not too difficult, the transmitter and receiver circuit scheme can be seen below.

Transmiter schematics

Receiver schematics

After the series finished, you can try to give the audio inputs on the transmitter and point the LED transmitter to the receiver. Maximum distance is a few meters may not be more than 10 meters, but you can listen to music without wires while using infra red.

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Simple FM transmitter with 2N3904

In this section discuss about the series of mini fm transmitter, with broadcast coverage of about 300-400 meters. when using a 9 volt working voltage, the transmit power of about 300 meters and when using the working voltage 12 volts, the range of about 400-450 meters, depending on the antenna you use.

This scheme of simple fm transmitter

For L1 and L2 windings 5 times the wrap, you can use a pen to fill melilitnya so neat and after lepaslah content of these pens. C5 is used for placement of broadcasting frequencies, can be tuned between 88-108 mhz, to reach further use steering antenna or Yagi antenna.

Part List

C1 = 0.001uF

C2 = 5.6pF

C3 = 10uF
C4 = 10uF
C5 = 3 - 18pF Adjustable capacitor

R1 = 270R

R2 = 4.7K

R3 = 10K

R4 = 100K

R5 = 4.7K

R6 = 4.7K

Q1 = 2N2222A

Q2 = 2N3904

L1 = 5 turn

L2 = 5 turn

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