Simple Infrared Control Extender

Posted on Feb 6, 2014

Lots of consumer electronic equipment like TV sets, VCRs, CD and DVD players employs infrared remote control. In some cases, it is desirable to extend the range of the available control and this circuit fits the bill, receiving the IR signal from your remote control and re-transmitting it, for example, around a corner into another room. Photodiode

Simple Infrared Control Extender
Click here to download the full size of the above Circuit.

D4 is connected to the inverting input of a 741 opamp through resistor R2 and capacitor C1. Since the BPW41 photodiode (from Vishay/Telefunken) needs to be reverse-biased to turn light energy into a corresponding voltage, it is also connected to the positive supply rail via R1. The non-inverting input of the 741 is held at half the supply voltage by means of equal resistors R3 and R4. The opamp is followed by a BD240 after-burner transistor capable of supplying quite high current pulses through IR LEDs D2 and D3. However, the pulsed current through the LD274s should not exceed 100 mA or so, hence a fixed resistor is used in series with preset P1. D1 is an ordinary visible-light LED that flashes when an IR signal is received from the remote. With regard to the setting of P1, do not make the IRED current higher than necessary to reliably reach the final destination of the IR signal. Also, the currents mentioned above are peak levels due to the small duty factor of the IR pulses, the average current drawn from the battery will be much smaller. The directivity of the IR LEDs and consequently the range of the control extender may be increased by fitting the devices with reflective caps.

Leave Comment

characters left:

Related Circuits

  • New Circuits



    Popular Circuits

    Simple timer
    Roland TR-707
    level shifting Increasing Voltage
    video turret
    1976 dodge aspen wiring diagram
    Controlling a LED using a switch
    Light Gate With Counter Using 555 And 4033
    Mains surge suppression
    Project [E-20] Infrared Data Transmitter