Motion-activated light
Lights for 30 s when someone passes. The PIR module’s output goes to 3.3 V for 30 s whenever it sees someone move. That is enough to turn on a logic-level MOSFET, which switches the 12 V LED strip; the 100 kΩ keeps the gate off when nothing drives it.
Build it in the labGuided build, test sheet and fault finding, free in your browser.
Parts list
- Bench power supply
- PIR motion sensor
- 2 × Resistor
- N-channel MOSFET
- 12 V DC LED bulb
Test procedure
Each test has an expected value and a pass range, like a factory test sheet:
- Quiet: off
- Someone passes: on
- Off again after the hold time
How it works
What it does: Lights for 30 s when someone passes.
Build it (guided or ready-made), then run its test procedure below. Every test has an expected value and a pass range, just like a factory test sheet.
Background
Porches, closets, stairs and toilets: light only when it is needed.