4THE NIGHT-LIGHT
THIS CIRCUIT IS A NIGHT-LIGHT THAT TURNS ON IN THE DARK.
THE CIRCUIT DIAGRAM
THE PARTS LIST
PART |
VALUE |
DESCRIPTION |
LDR |
~10 k to ~200 kΩ |
Light-dependent resistor (photoresistor) with around 5 to 10 kΩ resistance in light and 200 kΩ or more in dark |
Q1 |
BC547 |
Any general-purpose NPN transistor |
R1 |
100 kΩ |
Standard resistor |
R3 |
470 Ω |
Standard resistor |
LED |
|
Standard-output light-emitting diode |
ABOUT THE CIRCUIT
This circuit turns on an LED when it gets dark. During the day, the light stays off, but at night, it can help ...
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