One of our readers sent us a link to this very simple PIR circuit. It’s a really easy way to conserve battery life on any interactive project. Check out the link for a circuit diagram and more information.

When we design lighting circuit, we would like to light up the LEDs only when there is somebody around. The PIR sensor is a motion sensor based on passive infrared sensor which senses infrared emitted by human body. I got the PIR Module “KC7783R” from local store, which includes the PIR sesnor and also the KC7783 motion detection IC.

More about a Simple PIR motion sensing


  • Greg Tedford

    Hi,
    Love the simplicity of your circuit.

    I want this circuit to drive some leds aka.. Interactive led table on youtube.

    I have some questions….

    In you schematic, what are the values of the resistors at the collector and base of the Bc337?

    Do you think this circuit would suit my needs and what are the costs of components less the blue leds?

    Thanks in advance….

    Greg.