The example circuit used in various situations, such as control lamps or other device that needs to be turned off when the daylight. It is based on LDR (Light Dependent Resistor) is a special resistor that varies its electrical resistance according to the amount of light falling on its surface.
The circuit shown is easy to assemble and uses a light sensor ldr as the 10K potentiometer regulates the working point for your application. When light focuses on the LDR, the transistor turns on the relay that can handle various types of loads. As the LDR does not have a rapid response, rapid variations of light undetected, as lightning.
The LED serves to indicate the state of the circuit active or inactive and in many cases can be omitted by placing a jumper in place. To feed the circuit uses a 12 volts / 500mA power supply .
Diagram Schematic
PCB for module light sensor
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| Component | Value |
| Resistor’s 1/4 watts 5% | |
| R1 | 1.8KOhms – Black, Gray, Red, Gold |
| R2 | 680 Ohms – Blue, Gray, Brown, Gold |
| LDR | LDR |
| P1 | 10k – Trimpot |
| Semiconductors | |
| Q1 | BC548 or equivalent – NPN Transistor |
| D1 | 1N4004 or equivalent – Diode |
| LED | LED 5MM – Led. |
| VCC | AK500/2 Power supply Connector |
| CN | AK300/3 Load Connector |
| Diversos | |
| K1 | Relay Onrom G5LE or equivalent |
| PCB, box, wires etc. | |
Download PCB in PDF format
Download PDF Mirror
WHAT IS THE VOLTAGE OF RELAY?
HI Alejandro
12V!
DOES THE CIRCUIT IS NORMALLY “ON”
Hi i’m Austine
I would like to know how to connect the lamp after finaprication
HOW TO PLACE LDR IN MULTISIM WAT IS THE NAME OF LDR IN MULTISIM
there is no ldr in multisim, you could use isis proteus instead.
Hey,
Can you give me PCB Design file in PDF format?
Thank You …
hello toni, i just wanted to ask on which output terminals of the relay will you put the motor that will serve as an output? C? NC? or NF? thanks in advance.
Hi May
C is input and NC is output, thanks!
how to use relays in controlling dim and dip switches in two wheelers? please send the circuit diagram to my mail.
haaiiiii,,
my name is jared
i want to ask to you
how much input voltage??
what is the function of the connector na, c, nf??
how the voltage used on the relay??
thanks…..
Hi Jared
12 volts
C = common
NA = normally open
NF = normally closed