IR remote control

infrared (IR) remote controller comprises the transmitter and receiver sections. The range of the transmitter can be increased up to 5 meter by using convex lens. Circuit Description of infrared (IR) remote controller Transmitter section: – The transmitter circuit of infrared (IR) remote controller is built around IC741 (IC1) wired as frequency square wave oscillator. Gate pulse from pin no 6 of IC1 is given to gate of SCR1 to drive IR LED1. Variable resistor VR1 is used to vary the generated frequencies. Receiver Section: – The receiver circuit of infrared (IR) remote controller consist an IC 741, photo transistor (T1) and medium power transistor (T2). Photo transistor receives the transmitted signal and given to pin 2 of IC2 for amplification. The amplified output from pin 6 of IC2 is given to base of relay driver transistor (T2) through non- polarized capacitor C5, diode D1 and resistor R8. Variable resistor VR1 is used to match the transmitting and receiving signal. Parts list: PARTS LIST Resistors (all 1⁄4-watt, ± 5% Carbon) R1,R2 = 100 KΩ; R3, R5, R8 = 1 KΩ; R4 = 15 Ω; R6 = 22 KΩ; R7 = 10 MΩ; VR1 = 1 MΩ; VR2 = 2.2 MΩ Capacitors C1, C3, C4 = 0.1 μF; C2 = 1 μF/100V; C5 = 2.2 μF/16V Semiconductors IC1, IC2 = 741; SCR1 = SN050; T1 = photo transistor; T2 = SL100; D1, D2 = 1N4001 Miscellaneous RL1 = 15V, 500Ω Relay; IR LED