Simple IR transmitter circuit

Transmitter circuit information

This is an IR transmitting circuit which can be used in many projects (I designed this to try to make my 3D glasses wireless). This IR transmitter sends 40 kHz (frequency can be adjusted using R2) carrier under computer control (computer can turn the IR transmission on and off). IR carriers at around 40 kHz carrier frequency are widely used in TV remote controlling and ICs for receiving these signals are quite easily available.

The circuit can be controlled using any TTL or RS-232C level control signal which makes the interfacing very simple. The circuit can be used for example for using computer to generate IR remote control signals or experimental IR data transmission.

IR transmitter circuit

The circuit works so that when the input (LEFT/RIGHT CONTROL) pin is in logic high state (+4..15V) the transmitter is on and when it is in logic low state (+1V..-15V) the transmitter is off.

Component list for IR transmitter

C1     1 nF
C2     10 nF
C3     220 nF
D1,D2  1N4148
D3     TIL31B (or other suitable IR LED)
R1     1 kohm
R2     22 kohm trimmer
R3     120 ohm
U1     NE555, LM555 or similar

IR receiver and sega glass interface circuit

I designed the circuit to make my Sega 3D glasses wireless, but system did not work as well as I wanted it to work. I used the circuit below to receiving the IR signals and controlling the IR glasses.

Sega 3D glass IR receiver

Component list

Amount  Component
  2     10 kohm resistor
  2     22 kohm resistor
  1     10 uF electrolytic capacitor
  1     100 nF capacitor
  1     10 nF capacitor
  1     78L05 regulator (normal 7805 works also)
  1     GP1U52X receiver module
  3     1N4148 diode
  1     2N2222 transistor (BC547 works also)
  1     3.5 mm stereo jack

Modification ideas

The circuit can be also used for slow serial data transfer by connecting RS-232 data output to the transmitter module left/right control pin and connect the output of GP1U52X receiver module to RS-232 data input through suitable RS-232 buffer circuit. Maximum data rates achievable are at around 1200-2400 bps speed.

GP1U52X is quite hard component to get outside USA (in USA Radio Shack sells it cat. No. 276-0137). European experiments can try to replace it with SFH 506 or SFH 507 from Siemens. According some comments I have got none of the components I mentioned (GP1U52H, SFH506, SFH507) are no longer available, so you might not be able to get those. I don't know what would be a good more modern component replacement, because I have not tried other types than those myself.

Tomi Engdahl <[email protected]>