BK-0624

Fridge door monitor KIT, 5V DC

Schematic diagram

The circuit uses a photoresistor to monitor the opening of the refrigerator door (the refrigerator's own lighting), and if it detects that the door has been left open for too long, it draws attention to this with an audible signal. The sound signal only sounds with a delay after the light is detected. The buzzer turns on with ~1 minute delay. Power supply: 9V DC Quiescent current consumption: <1mA Active current consumption: 15mA (when light is active) Maximum current consumption: 41mA (when beeping) The set contains parts to be soldered! Add to basket (Part no.: 100.472.43) 1+: 620 Ft 5+: 435 Ft 10+: 407 Ft 20+: 390 Ft 50+: 374 Ft

Assembly diagram

Product picture

1

R5	1K 0.25W
R2	10K 0.25W
R4	10K 0.25W
R6	470K 0.25W

2

U1

NE555

3

C2

100nF (104)

4

R1

LDR

5

Q2

S8050 (NPN)

6

Q1

SS8550 (PNP)

7

BZ1

BUZZER

8

C1

100uF

The supply voltage must be connected to the (+) and (-) points marked on the circuit. The polarity and actual voltage of the power supply must always be carefully checked before connecting to the circuit.
(+) = Positive supply voltage pole (usually red)
(-) = Negative supply voltage pole (usually black)

After wiring the 9V supply voltage with correct polarity, the circuit immediately ready to use.
Make sure that the circuit does not touch the metal parts of the refrigerator!