Burglar alarm,. switches for home appliances, sensors of control in a production line are only a small part of the scope of capacitive relay. It can be used, for example, in the simplest household automation: sat in a chair turned on the lamp, the music began, earned a fan, etc. in short, the scope of this relay will prompt imagination, creative thought themselves radio Amateurs.
The range of the relay depends on the accuracy of the tuning capacitor C1, and the design of the sensor. The author has the maximum distance to which the relay responds, equal to 50 cm.
A schematic diagram of a capacitive relay shown in Fig.1, image Assembly and the circuit Board in Fig.2, and the design of the inductive coil with the placement of it and the sensor on the Board in Fig.3.
Coil L1 is wound on a multi-polystyrene frame from the contours of transistor radios and contains 500 turns (250 + 250) with a branch of the middle wire PEL-0.12 mm. Winding - in bulk.
The sensor is mounted perpendicular to the plane of the PCB. He represents a segment of insulated bonding wire length from 15 to 100 cm, or square, made of the same wire, with sides of 15 cm to 1m.
The C1 capacitor - type CPC-M, the other type K50-6. As the relay selected RES-10, passport RS4.524.312, can also be applied to RES-10, passport RS4.524.303, or RES-55A, passport 0602. Diode VD1 can be deleted, as it is necessary only to protect the circuit from accidental reverse polarity of power.
Configurable capacitive relay capacitor C1. The first rotor C1 must be set to minimum capacitance. this will trigger the relay K1. Then the rotor is slowly rotated in the direction of increasing capacity to turn off the relay K1. The smaller the adjusted capacity of the capacitor, the more sensitive capacitive relay and the greater the distance that the sensor can react to the object. When configuring the capacitor housing body and the hand with the dielectric screwdriver must be kept at the greatest possible remove from the Board.
Author: V. herdsmen, Novosibirsk, Russia; Publication: N. Bolshakov, rf.atnn.ru