As shown in the circuit to light when the intensity 700lx above action, this time through the
phototransistor and the transistor BFY52 BPX25 to thyristor BTY91 / 800R trigger current. When the light is irradiated on the phototransistor, the trigger pulse is always in the positive half weeks after the starting point occurred about 6 degrees each, by the arithmetic mean of the load flows through the half-wave DC current up to 16A. Regulator BZY88 / C5 and transistor T1 and the resistor 390 is connected to Europe, for limiting the trigger circuit voltage does not exceed 6V. Diode BYX45 / 800R for blocking the negative half-cycle grid voltage, resistors and capacitors 0.1uF 33 Europe for protecting thyristors against overvoltage.