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Automatic Dusk-to-Dawn Switching Without a Microcontroller
The Relay Light Controlled Module combines a light sensor and a relay on one board, so it can switch a load when the surrounding light level changes. That means you can build simple dusk-to-dawn or light-triggered systems without adding a separate microcontroller.
It is a useful module for outdoor lights, night indicators, greenhouse controls, and energy-saving projects that need automatic response to ambient light.
Important: The onboard potentiometer lets you adjust sensitivity, so you can tune the trigger point to match the room, enclosure, or outdoor light conditions.
Why you'll like it
- Works on its own: No controller needed for basic light-triggered switching
- Adjustable sensitivity: Tune the light threshold on the board
- Relay output onboard: Easy switching for AC or DC loads within rating
- Fast to install: Good for simple automation jobs
- Good for day/night projects: Useful in outdoor or window-side builds
What you can build
Use it for dusk-to-dawn lamps, sign lighting, greenhouse shade control, nighttime alarms, and other simple projects that react to ambient light.
Starter bundles
Pair it with an Arduino-compatible board, ESP32, or Raspberry Pi, plus jumper wires, a suitable power supply, and a small load for bench testing.
Recommended add-ons
Useful add-ons include terminal block, breadboard, power modules, fuses, and enclosure, especially when you are working with higher voltages or inductive loads.
Technical specifications
| Product | Relay Light Controlled Module |
|---|---|
| Main sensing element | Photoresistor / LDR |
| Function | Turns relay on or off based on ambient light |
| Relay load | 10A @ 250VAC or 10A @ 30VDC |
| Adjustment | Onboard potentiometer for sensitivity |
| Controller requirement | Not required for basic operation |
Pinout & power notes
Power the module from its rated supply, adjust the onboard potentiometer, then wire the target device to the relay output. Test the trigger point under real lighting conditions before final installation.
What’s in the box
1 × Relay Light Controlled Module
Frequently Asked Questions
Do I need Arduino to use this module?
No. It can work as a stand-alone light-triggered relay.
No. It can work as a stand-alone light-triggered relay.
Can I adjust when it turns on?
Yes. The onboard potentiometer changes the sensitivity threshold.
Yes. The onboard potentiometer changes the sensitivity threshold.
What is a common use for it?
Outdoor lights that turn on when the area gets dark are one of the most common uses.
Outdoor lights that turn on when the area gets dark are one of the most common uses.
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Schools / class POs: we accept Purchase Orders for accredited schools and universities. contact us with your PO details.
Returns: 7-day inspection window for DOA units. Email proof of issue and we ship a replacement.
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