Relay Circuit Detects Light Change

Configured with capacitive coupling (by inserting a small cap between photo-transistor and bipolar transistor), this relay circuit will respond only to rapid changes  in light while ignoring normal gradual changes in ambient light. Rapid changes can be produced by light interruption or turning on/off lamps, while gradual light changes can be produced by clouds or  sunrise.  Here is the schematic diagram of the circuit:

LIGHT CHANGE SENSOR DRIVES RELAY circuit schematic diagram

This entry was posted in Control Electronics, Lighting and LED Circuit and tagged . Bookmark the permalink.,
Possibly Related to "Relay Circuit Detects Light Change" Circuits

  • Flash-Triggered Pulse Stretcher Using Classic Monostable Circuit
    This is a flash triggered (photo-driven) circuit which produce a pulse with constant predetermined wide. This circuit can be used to control any device which is required to be synchronized with optical trigger/flash light.  The pulse can be used to … Continue reading →...
  • General Infrared Remote Controlled Relay
    This relay circuit is controlled by almost any type of infrared remote controller. This circuit works on assumption that almost all remote controller use high frequency modulated infrared light. By filtering out un-modulated or low frequency modulated signal, this circuit … Continue reading →...
  • Simple Ac Light Bulb Flasher
    This is the simplest circuit that mains powered light bulb to flash. To build this circuit we do not need a much money. This circuit can be used in small parties and similar occasions. This circuit is made by wiring … Continue reading →...
  • L200 Light Controller
    This is a circuit of L200 light controller. The output of this circuit is controlled by the surrounding environment’s brightness.  If the brightness increases, the output voltage will increases as well. Here is the circuit : The R1 and photoresistor … Continue reading →...
  • Five-Decade Dynamic Light-Level Meter
    This is a Portable light-level meter circuit with five-decade dynamic range. This uses  a single cell battery as the power supply. To calibrate this circuit, use an appropriate illumination, then adjust R2 so that the output equals the reference. To … Continue reading →...

Comments are closed.