Infa-Red Remote Control

Description

I have received a number of emails requesting schematics for infa-red remotes. So here is one. This remote transmits a tone using an infa-red LED. This tone is decoded by the receiver. Since the receiver only switches when it "hears" the tone, there are no accidental activations.

Circuit diagram For Transmitter

Infa-Red Remote Control-Circuit diagram For Transmitter

Circuit diagram For Receiver

Infa-Red Remote Control-Circuit diagram For Receiver

Parts:

  • R1 22K 1/4W Resistor
  • R2 1 Meg 1/4W Resistor
  • R3 1K 1/4W Resistor
  • R4, R5 100K 1/4W Resistor
  • R6 50K Pot
  • C1, C2 0.01uF 16V Ceramic Disk Capacitor
  • C3 100pF 16V Ceramic Disk Capacitor
  • C4 0.047uF 16V Ceramic Disk Capacitor
  • C5 0.1uF 16V Ceramic Disk Capacitor
  • C6 3.3uF 16V Electrolytic Capacitor
  • C7 1.5uF 16V Electrolytic Capacitor
  • Q1 2N2222 NPN Silicon Transistor or 2N3904
  • Q2 2N2907 PNP Silicon Transistor
  • Q3 NPN Phototransistor
  • D1 1N914 Silicon Diode
  • IC1 LM308 Op Amp IC
  • IC2 LM567 Tone Decoder
  • LED1 Infa-Red LED
  • RELAY 6 Volt Relay
  • S1 SPST Push Button Switch
  • B1 3 Volt Battery or Two 1.5V batteries in series
  • MISC Board, Sockets For ICs, Knob For R6, Battery Holder
  • RELAY 6 Volt Relay

Notes:

  1. To adjust the circuit, hold down S1 while pointing LED1 at the receiver. Adjust R6 until you hear the relay click.
  2. You can increase range by using a high output LED for LED1.
  3. Bright light will stop the receiver from responding to the transmitter.