Motion sensor LED nightlight

Motion sensor LED nightlight with rechargeable phone battery. Simple project, 3D printer and soldering iron is used.

Parts : HC-SR501 pir motion sensor, LED green strawhat 8mm, micro USB adapter PCB, Mosfet (any type, must open at 2V gate voltage), resistors.

Print the 3D housing, drop in the two PCBs and solder them in position together (asymmetrical, see pic). Remove the PCBs and mount the rest of the components. Cut the 3 inner tracks on the micro USB adapter board, gaining 3 solder points. SOP-8 type MOSFET is soldered on GND pin 2-3(source) , pin 4(gate) to module OUT. SOT-23 type MOSFET soldered on upside down. Assemble all parts and finally a drain series resistor 100-220ohm in series with the LED is soldered on.

The (recycled) Nokia or similar battery is charged from USB thru 10 ohm and a diode (part of the HC-SR501), please see schematics. The circuit is simple but the low charge current needs 10-20 hours charge time.

The sensor uses very little current, normally