Schematic diagram of a sound and light dual control energy-saving switch circuit

This circuit introduces an energy-saving switch with dual control of sound and light. During the day, the optical fiber is strong, and the photosensitive tube D is turned on by the light. At this time, regardless of whether there is sound triggering or not, pin 1 of the IC is low level, and passes through c, d, and e. , after f is applied, pin 8 is low level, the thyristor is cut off, and the bulb does not light up; at night, the photosensitive tube D is high resistance, and the level comparator exits the forced reset state. At this time, if there is a sound that triggers HTD, after amplification and shaping, the level of pin 1 is higher than the threshold level, the circuit flips, and C3 is charged, so that pin 5 can maintain a high level for tens of seconds after the sound disappears. , pin 8 is at a high level, triggering the thyristor to conduct, and the bulb lights up.