NOISE-RESISTANT CAPACITANCE DEVICE FOR SECURITY ALARM Russian patent published in 2011 - IPC G08B13/00 

FIELD: electricity.

SUBSTANCE: device includes high-frequency generator in series connected to signal processing channel including input LC-loop connected in parallel to antenna-sensor and detector; to the capacitance device there introduced is the second signal processing channel identical to the first channel and including the input LC-loop in parallel connected to antenna-sensor and to detector, and low-pass filter the input of which is connected to the detector output. At that, output of one of signal processing channels is connected to amplifier input, and output of the second channel is connected to common amplifier circuit wire, without connecting the common amplifier wire to common wire of signal processing channels; at that, power is supplied to amplifier from independent source. As per the second version of invention, outputs of signal processing channels are connected to inputs of signal comparison circuit - comparator the common wire of which is connected to common wire of signal processing channels; at that, independent power source is excluded.

EFFECT: improving reliability and interference immunity.

2 cl, 6 dwg