In various automobile security systems are often used sensors mechanical oscillations of the body. The described sensor is designed for digital security the device and its operation is based on the phenomenon of excitation current in the conductor.
crossing the magnetic field lines. As the sensor used modified pointer instrument coil system - small microammeter from a cassette recorder.
Refinement is that at the end of the arrow strung a piece tubular solder, flux released from, a length of 4 mm and a diameter of 3 mm To the ends of the scale glue the cubes side 5 mm of foam. The sensor is installed in the cabin down arrow, and its fluctuations should occur in the plane transverse to the axis car.
Schematic diagram of the sensor shown in the figure.
Fluctuations in the hands of the sensor are amplified and normalized by the comparator DA1. Variable resistor R3 serves as a sensitivity control, the maximum of which meets the minimum offset voltage.
The capacitor C2 dampens oscillations (ringing) at the output of the comparator when the switching output voltage.