HC-SR501: a cheap 0.70$ PIR motion sensor
replaced the onboard 15kOhm output resistor with a wire.
the onboard PIR IC “BISS0001” has a maximum output current of 10mA at 5V. a bit less if, like the HC-SR501, driven at 3.3V.
the output voltage is 3.3V as well.
the PIR sensor activates a stepper motor driver i’ve built a few years ago.
a small and long tube of heatshrink attached to the stepper motor works quite nicely. the cat can’t tear it apart because it’s slippery.