Design of a triggering circuit of overvoltage protection with an asymmetric element

The design of the triggering circuit (1) of the overvoltage protection device with an asymmetric element, specified for actuating a spark gap (4) in symmetric or asymmetric arrangement of main electrode I (5), connected to input terminal I (2), of main electrode II (6), connected to input terminal II (3), and the auxiliary electrode (7).The main electrode I (5) of the spark gap (4), which is connected via a thermo-sensitive disconnector (21), and also via a parallel combination of varistor II (9) and capacitor I (16) to electrode I (13) of the asymmetric three-pole lightning arrester (12), whose middle electrode (15) is connected via the primary winding (20) of the transformer (18) to main electrode II (6) of the spark gap (4), whose auxiliary electrode (7) is connected via varistor I (8) to electrode II (14) of the asymmetric three-pole lightning arrester (12), which is connected via the secondary winding (19) of the transformer (18) to main electrode II (6) of the spark gap (4), and at the same time, the thermo-sensitive disconnector (21) is coupled via the thermal coupling (22) with varistor II (9) and, at the same time, the voltage at the asymmetric three-pole lightning arrester (12) is as follows: static ignition voltage U1 between electrode II (14) and the middle electrode (15) is higher than static ignition voltage U2 between the middle electrode (15) and electrode I (13).˙