PIR light switch

 

 

Synopsis

Too lazy to switch on the lights by yourself? annoyed with the
commercial versions that shut off and has to be "waved" on again?

Heres a simple DIY that amends those first world problems

 

Components needed

resistors
capacitors
mosfet (P-channel) IRF9510 in this case
12V wall plug
LED strips 12V
PIR sensor
BJT transistor NPN BC547
diodes, tvs -not really needed

PIR sensor TDL-718

this component runs on 12V at gives a short 3s pulse of 3.3V
when sensing movement.

Generic ebay PIR sensor

Output connected via resistor to PNP transistor
shorting out the capacitor and thus allowing the mosfet
to allow current to pass.

Since cap voltage will pass full saturation the LEDs wil fade on / off

 

Schematic

Resistor R1 sets the ontime icw cap C1
allow R2 to protect transistor

Basic schematic, I later added som tvs diodes

Prototype board

Components on board

 

Installation

First prototype board

Filter cap and tvs diode due to poor wiring in house

Lights up ok, low exposure

PIR sensor under cabinet,3D printed enclosure

generic 12V 1A supply

 

Testing the setup

Cabinet door are at the paintshop..

 

LEDs off

LEDs on

 

 

Youtube

 

 

 

-200929