Ultrasonic switch


Posted on Feb 6, 2014

The transmitter part of the circuit is build around IC1(NE 555). The IC1 is wired as an astable multi vibrator operating at 40KHz. The output of IC1 is amplifier the complementary pair of transistors ( Q1 & Q2) and transmitted by the ultrasonic transmitter K1. The push button switch S1 is used the activate the transmitter. The receiver uses an ultras


Ultrasonic switch
Click here to download the full size of the above Circuit.

onic sensor transducer (K2) to sense the ultrasonic signals. When an ultrasonic signal is falling on the sensor, it produces a proportional voltage signal at its output. This weak signal is amplified by the two stage amplifier circuit comprising of transistors Q3 and Q4. The output of the amplifier is rectified by the diodes D3 & D4. The rectified signal is given to the inverting input of the opamp which is wired as a comparator. When ever there is an ultrasonic signal falling on the receiver, the output of the comparator activates the transistors Q5 & Q6 to drive the relay. In this way the load connected via the relay can be switched. The diode D5 is used as a free wheeling diode.




Leave Comment

characters left:

Related Circuits

  • New Circuits

    .

     


    Popular Circuits

    GP display controller
    Portable Headphones Amplifier
    Speech activity detector for telephone lines
    Loudspeaker Protector Circuit
    silicon fuzz
    led night light lamp circuit
    UPS Circuit For Cordless Phones PCB
    Guitar Vibrato circuit
    NE5532 manufactured by headphone amplifier circuit
    555 tachometer circuit diagram



    Top