# Mini Reed

![](https://451694785-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MPda5vaSVRKTQ6AoAmb%2Fuploads%2Fgit-blob-f103020e2e0ae3250ad7260979e2d48e6f2f0ef5%2Fimage.png?alt=media)

The reed switch is connected between the two outer pins on the PCB. Without a magnetic field the contacts remain open. A built-in 10 K ohm resistor is connected between the centre pin and the ‘S’ pin. It can be used as a pull up or pull down resistor.