Light Activated Relay
This is same circuit as above with the addition of a photo resistor to trigger the flip flop instead of a push button. The bias resistor in series with photo resistor was chosen so that sufficient voltage is present at the base of the 2N3904 to supply current to the circuit in ambient lighting conditions. The circuit should toggle when the photo resistor is hit by a flashlight beam or other fast changing light source. Slow changes in light intensity will have no effect unless the light gets too bright to maintain sufficient bias for the 2N3904.
Como indica este sitio de pronósticos

Light Activated Relay circuit
Title: Light Activated Relay
electronic circuit
Source: unknown
Published on: 2007-07-21
Reads: 904
Print version: ![]()
Other electronic circuits and schematics from Motor, light and power control
-
Expandable 16 Stage LED Sequencer
-
Simple DC motor PWN speed control
-
Running Message Display
-
Emergency Light
-
Dark-activated LED or Lamp Flasher
-
Sunrise Lamp
-
Fading LEDs
-
Brightness of multiple displays control circuit
-
Pulse Width Modulation DC Motor Control
-
Flashing Neons (NE-2 / NE-51)
