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DIY Kit Brightness Light Detector Dark Alarm Photosensitive Sensor Kit Electronic Soldering Practice Kits
$2.09$2.9930%
00d : 00h : 00m : 00s
Item ID: 13603
Product Details
Description:
This circuit is used to detect ambient light and emit sound and light alarm when the light is bright.
Supply voltage: DC3-5V
Principle:
RP, RG, Q1, Q2 constitute a light control switch; R1, R2, C2, Q3, Q4, BP constitute a complementary oscillation circuit. When the photoresistor RG is under illumination, the resistance becomes smaller and the voltage of RG drops.
When the voltage is lower than the bias voltage of Q1, Q1 is turned off and Q2 is turned off. The oscillating circuit stops supplying power and the buzzer stops. Conversely, in the dark environment, the photoresistor RG resistance rises, the voltage on RG rises, Q1 and Q2 turn on, the oscillating circuit energizes, the signal enters the passive buzzer, and the buzzer sounds an alarm.
