Light control circuit diagram using 555 time base circuit

What is introduced here is a light control circuit using a 555 time base circuit. Since it does not require a dedicated transmitter, it is a telemetry circuit. Photodiode VD1 is used for light detection and conversion. Photodiodes with different properties can be used as needed to convert infrared light or visible light into electrical signals. IC1 uses NE555 to form a Schmitt trigger, which shapes and power amplifies the received optical signal to drive subsequent circuits. The driving current reaches 200mA, which can directly drive relays or micro motors.

As shown in the figure below, this circuit is controlled by positive logic, that is, ICl outputs a high level when there is light and a low level when there is no light. If negative logic control is required, just change the positions of VDl and R1 with each other. The C1 and R2 integrating circuits filter out interference pulses to prevent malfunctions. The power supply voltage range is 5V to 12V. During debugging, adjust R1 as needed to make the circuit have appropriate sensitivity. This circuit can be used for infrared detection, anti-theft alarm or dangerous entry alarm; if the light detection head of this circuit detects the production process, the output is connected to the electronic counter, and can also be used to generate online product quantity detection and printing machine paper quantity detection.