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














CAR-REVERSING HORN WITH FLASHER

Related Circuits

  • Speed Checker for Highways
  • Automatic Washbasin Tap Controller
  • Water Pump Controller
  • Security System Switcher
  • Battery-Low Indicator

  • Subscribe to Electronicsforu.com
       

    CAR-REVERSING HORN WITH FLASHER

    ASHOK K. DOCTOR


    Here is a simple circuit that starts playing the car horn whenever your car is in reverse gear. The circuit (refer Fig. 1) employs dual timer NE556 to generate the sound. One of the timers is wired as an astable multivibrator to generate the tone and the other is wired as a monostable multivibrator.



    Fig. 1: Car reverse horn

    Working of the circuit is simple. When the car is in reverse gear, reverse-gear switch S1 of the car gets shorted and the monostable timer triggers to give a high output. As a result, the junction of diodes D1 and D2 goes high for a few seconds depending on the time period developed through resistor R4 and capacitor C4. At this point, the astable multivibrator is enabled to start oscillating. The output of the astable multivibrator is fed to the speaker through capacitor C6. The speaker, in turn, produces sound until the output of the monostable is high.

    When the junction of diodes D1 and D2 is low, the astable multivibrator is disabled to stop oscillating. The output of the astable multivibrator is fed to the speaker through capacitor C6. The speaker, in turn, does not produce sound.

    Assemble the circuit on a general-purpose PCB and enclose in a suitable cabinet. Connect the circuit to the car reverse switch through two wires such that S1 shorts when the car gear is reversed and is open otherwise. To power the circuit, use the car battery.

    The flasher circuit (shown in Fig. 2) is built around timer NE555, which is wired as an astable multivibrator that outputs square wave at its pin 3. A 10W auto bulb is used for flasher. The flashing rate of the bulb is decided by preset VR1.




    Fig. 2: Flasher circuit

    Assemble the circuit on a general-purpose PCB and enclose in a suitable cabinet. The flasher bulb can be mounted at the car's rear side in a reflector or a narrow painted suitable enclosure.

    EFY note. A higher-wattage bulb may reduce the intensity of the headlight. You can enclose both the car-reversing horn and flasher circuits together or separately in a cabinet in your car.


     

    Related Circuits


    Post Comment | 0 Comments




    Electronics Buzz
    Electronics a key focus area in Modi-Abe meet in Japan
    Top 15 PCB manufacturers in India
    Global telecom vendors likely to meet local value-addition targets
    Indian manufacturing sector to see a new dawn soon with new FDI decisions
    TE Connectivity eyes major manufacturing sectors in India
     
     
      Magazines
    Electronics for You
    LINUX for You
    Facts for You
    Electronics Bazaar
    Portals
    electronicsforu.com
    efytimes.com
    bpotimes.com
    linuxforu.com
    Directories
    Electronics Annual Guide
    Events
    EFY EXPO
    EFY Awards
    EduTech Expo
    OSIWEEK Expo
    News Verticals
    Electronics
    Infotech
    Linux & Open Source
    Consumer Electronics
    Science & Technology
    BPO
    Educational Institute
    EFY Techcenter
    Kitsnspares.com
     
    © 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