Introduction to the Reed Switch¶
The reed switch is a sensor operated by the presence of magnetic field. As it's a switch, it usually is open by default and closes when magnetic field is applied. Here's a short overview.
How it works¶
The reed switch is made up of two magnetizable and flexible metal reeds hermetically sealed in a tube, usually made of glass. By default, the tips of the reeds are separated by a small gap when the sensor is open. Applied magnetic field will then make the two reeds attract and close - thus completing an electrical circuit. When there's no magnetic field present anymore, the small gap opens between the flexible reeds again.
Reed switch in our devices¶
We use the CotoClassic CT 05 reed switch.
The sensor is located on the same side of the device as the button - very close to it on the right side when viewed from the top as you can see on the picture right here:
When it comes to the SimpleIndustry, the same PCB board is used but it's in a vertical position, which means you can find the reed switch right on top of the device, in about ¾ of the length of the device.
Most reed switch use cases require using a magnet together with the device and we can supply magnets together with your order. You can look for magnets on our eshop.
Things the reed switch can do¶
Simple on/off detection.
Counting the number of switches.
Recording the time between on/off switches.
Common use cases¶
- Monitoring doors and windows
- Monitoring if safery equipment is in its place
- Monitoring post boxes
- Monitoring how long a door/cover in industrial environment is open
- Counting the number of openings of doors, manholes, windows etc.
- Counting internal mechanism revolutions in e.g. soap dispensers
- Monitoring room occupancy (usually public toilets)
- And others...