Login | Register | Advertise | About Us | Search | Contact Us |
    H O M E   >>  C I R C U I T   L A B

Infrared Remote Control Timer

Related Circuits

  • AC-Powered Led Lamps Without rectifiers
  • Speed Controller for DC Motor
  • FM Bug
  • Speed Checker for Highways
  • Automatic Washbasin Tap Controller



    This infrared remote control timer can be used to turn an appliance on/off for a period of 0.11 second to 110.0 seconds.

    The circuit comprises two sections, namely, the transmitter section and the receiver section. Fig. 1 shows the IR transmitter section. The astable multivibrator NE555 (IC1) is used to generate a 10kHz modulated IR signal. The output of IC1 is connected to the base of pnp transistor T1 via resistor R2. Two infrared LEDs (IR1 and IR2) are connected in series between the collector (via resistor R3) and ground. When switch S1 is pressed, the IR LEDs transmit the modulated IR signal of 10-11 kHz. This frequency can be changed with the help of VR1 potmeter.

    Fig. 1: IR transmitter section

    In the receiver section shown in Fig. 2, two photodiodes (IR3 and IR4) receive the IR signal transmitted by the IR transmitter. Transistors T2 and T3 amplify the weak signal. The amplified signal is filtered by capacitors C6 and C7. The amplified and filtered signal is now fed to the inverting input pin 2 of op-amp IC2 (IC 741). The output of IC2 is further connected to trigger pin 2 of timer NE555 (IC3) that is used as a monostable multivibrator whose frequency may be varied with the help of potmeter VR3.

    Fig. 2: IR receiver section

    When switch S1 of the transmitter is pressed, the modulated IR rays are generated, which are received by photodiodes in the receiver section and amplified by the amplifier circuit. Theoutput of op-amp goes low to trigger the monostable. Then high output at pin 3 of IC3 activates the two changeover relay RL via transistor T3 (BC548) for a preset time.

    The on/off time can be set in the timer with the help of VR3 and C10. Switch S2 is used to reset the monostable. If you want to turn the appliance on for a preset time, connect the appliance via relay RL(a). On the other hand, if you want to turn the appliance off for a preset time, connect the appliance via relay RL(b). The timer can be reset by pressing reset switch S2. The circuit works up to 3 metres without using any focusing lens. However, you can increase the operating range by using focusing lens.


    Related Circuits

    Post Comment | 0 Comments

    Electronics Buzz
    STMicroelectronics launches satellite demodulator for fast & affordable broadband
    SIGFOX and TI collaborate to deliver cost-effective IoT connectivity
    NComputing captures over half of the Indian enterprise client device market
    Infineon Technologies acquires outstanding shares of LS Power Semitech
    Samsung Electronics unveils ultra-compact LED chip scale packaging technology at Lightfair International 2015
    Electronics for You
    LINUX for You
    Facts for You
    Electronics Bazaar
    Electronics Annual Guide
    EFY Awards
    EduTech Expo
    OSIWEEK Expo
    News Verticals
    Linux & Open Source
    Consumer Electronics
    Science & Technology
    Educational Institute
    EFY Techcenter
    © Copyright 2012 EFY Enterprises Pvt. Ltd. All rights reserved.
    Reproduction in whole or in part in any form or medium without written permission is prohibited. Usage of the content from the web site is subjectT etor ms and Conditions