electronic combination lock circuit


Posted on Feb 6, 2014

a simple electronic combination lock using IC LS 7220. This circuit uses a relay for controlling any type of device when the combinations of four digits are pressed. Keypads are used as input here to enter the digits and the correct combination will activate the relay and the door or deice can be operated. The combinat


electronic combination lock circuit
Click here to download the full size of the above Circuit.

ion can be set here by connecting the appropriate keys to the pins 3, 4, 5 and 6 of the IC through Header. Unselected keys are connected to the pin 2. For example if 4568 is your combination then it is to be connected to 3, 4, 5 and 6th pins and rest of the keys are connected to pin 2. Thus any four key combination can be created using this. The 2nd pin of this IC was reset so whenever any other keys connected to pin 2 is pressed it will reset the device and the digits have to be re-entered. When the correct combination is pressed the output will be activated for a preset time determined by the capacitor C1. Increase C1 value to increase on time. Using this circuit you can really construct a high efficient lock system.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    A class and push-pull
    Headphone Amplifier
    LED runner with 74LS163
    Antenna ground loop Isolator
    Simple humidity detector
    29Mhz-amplifier
    Bias Supply For Microwave Preamps
    Pulse-Frequency Modulated Receiver
    Linear Video Amplifier SECAM PAL and NTSC
    Stabilized DC Power Supply with Short-Circuit Indication
    Power Amplifier 2000 Watt
    Design on the basis of the mechanically controlled digital frequency meter of one piece
    arduino scr
    HIP6302V Microprocessor CORE Voltage Regulator Multiphase Buck PWM Controller
    Potentiometric voltmeter
    Programmable Home Security Alarm System
    Simple and practical electric vehicle anti-theft alarm circuit diagram
    Night circuit diagram showing target



    Top