This slit light switch is a simple plastic sensor with two elements - an IR LED and an IR photo-transistor, located on a U-shaped space. You can control the IR LED and turn it on to transmit IR light through space to the detector on the other side. This makes it perfect for detecting when there is something in the slot - when there is something that blocks the light, the sensor turns off, when the object disappears, the sensor receives the IR light and turns on.

These sensors are handy when you want to detect if something has passed through the sensor slot, we think it's great when they're paired with our slot encoder wheels to measure the speed of rotation. This sensor is extra fancy with a red LED on the side to alert you when the sensor is triggered, and an integrated protection circuit.

We will mention the disadvantage of this sensor is that the circuits inside need power supply - the Wine line must be supplied with at least 5V. But, the output transistor is open collector so you can connect a 3V pullup resistor for 3.3v logic if necessary. So, as long as you have a 5V output power, you can use it with a 3V device as well as with a Feather card.

This version has no cable attached, but it has beautifully labelled pins:

    Symbol (+) - VCC (logic circuit power supply 5-24V)
    L - LED configuration, see technical data sheet for options but we simply link to the VCC
    OUT - transistor output. As the collector is open, you must connect a pullup resistor to your logical level.
    (-) symbol - mass

Technical details

    Weight: 2g
    Space width: 5mm
    Detection distance: 5mm
    Light source: Infrared LED (940 nm)
    Supply voltage: 5 to 24 VDC ±10% (ripple (p-p)10% max.)
    Current consumption: max. 35 mA
    Control output (message type) : NPN Open collector output
    Control output (load supply voltage): 5 to 24 VDC
    Control output (charging current): max. 100 mA
    Response frequency elements: 1 kHz min. (average 3 kHz)
    See the data sheet for more information and dimensional drawings, this is equivalent to part #EE-SX672.