This kit works as a "light" detector which energizes a miniature relay when the CDS (Cadmium Sulfide) photo resistor detects bright light. The relay is de-energized when it detects subdued light. A trim pot is provided for adjusting the sensitivity of the detector.
Applications : automatic corridor or porch light control, "chop-beam" intrusion alarm, . . .
VR1 ------ Trimmer potentiometer, 1M Ω (#105) (sensitivity control)
D1 -------- Diodes :(either one of:) [salah satu :] 1N4001, 4002, ... 4007
C1 -------- (either one of:) [salah satu :] 22 µF, 33µF, 47 µF electrolytic capacitor
Q1, Q2 --- Transistors, general purpose NPN transistors (* see diagram)
LED1 : Light-emiiting diode -- 3 or 5mm
RLY-1 : Miniature relay, coil=DC 9V, single pole-double throw contact
CDS : Photo cell (or light dependent resistor)[perintang cahaya]
Miscellaneous items: etched & drilled PCB, 9V battery clip, etc., ...
Resistors (1/4W) :
R1, R5 -- 1 K (brown-blk-red) [cok-hit-mer]
R2 ------- 5.6 K (green-blue-red) [hij-biru-mer]
R3 ------- 6.8 (blue-grey-gold) [biru-kel-emas]
R4 ------ 3.3M (orange-orange-green) [oren-oren-hij]
The above project is available in DIY kit . Click here to view price list.