Ultrasonic-transceiver


Posted on Oct 17, 2012

The LM1812 is a complete ultrasonic transceiver on a chip designed for use in a variety of pulse-echo ranging applications. The chip operates by transmitting a burst of oscillations with a transducer, then using the same transducer to listen for a return echo. Ifan echo of sufficient amplitude is received, the LM1812 detector puts out a pulse of approximately the same width as the original burst. The closer the reflecting object, the earlier the return echo.


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

Echos could be received immediately after the initial burst was transmitted, except for the fact that the transducer rings. When transmitting, the transducer is excited with several hundred volts peak to peak, and it operates in a loudspeaker mode. Then, when the LM1812 stops transmitting and begins to receive, the transducer continues to vibrate or ring, even though excitation has stopped. The transducer acts as a microphone and produces an ac signal initially the same amplitude as the transmit pulse. This signal dies away as is governed by the transducer"s damping factor, but as long as detectable ringing remains, the LM1812"s detector will be held on, masking any return echos.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

Timer LM555 Circuits
FM reciever with LM386
Pulse-amplitude-discriminator
4-Decade Square-Wave Generator
Vacuum Tube Preamplifier Analysis and SPICE Simulation
Compensation Resistor Stabilizes SMPS at High Duty Cycles
Fun and easy to build buzzer circuit
JFET PREamp
simple magnitude comparator
Switching Voltage Regulator
Precision Power Supply 0-40V 0-2A adjustable current limiting
A Timer That Re-Triggers At Regular Intervals
Linear AC voltmeter circuit diagram



Top