STABILISED CAPACITIVE ALARM DEVICE Russian patent published in 2010 - IPC G08B13/26 

FIELD: information technology.

SUBSTANCE: alarm device has the following series-connected components: a stabilised trigger signal conditioner, a detector, a signal amplifier, a threshold device and an actuating mechanism, as well as a high Q-factor input LC-circuit connected at the input of the stabilised trigger signal conditioner, and a circuit for stabilisation and automatic adjustment of the high Q-factor input LC-circuit, which has a compensation unit and a control unit for the said compensation unit. The compensation unit includes elements with electrically-controlled capacitance which is transferred through a coupling capacitor to the high Q-factor input LC-circuit for its adjustment and keeping its operation mode within given limits. The input of the compensation unit is connected to the output of the control unit, to the input of which a control signal is transmitted from the output of the trigger signal conditioner through the detector in order to control the compensation unit.

EFFECT: increased reliability and improved technical characteristics of the device.

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