Starting Electronics Needs Your Help!
It is that time of the year when we need to pay for web hosting and buy new components and equipment for new tutorials. You can help by making a donation. Contribute to this website by clicking the Donate button. The total will be updated once daily. (You may need to clear your browser cache to see the updates.)
Target Amount: $2000
Amount Raised: $1539.10
Top Donor: C.C. $100
Created on: 30 July 2012
A reed switch is a magnetically operated switch – moving a magnet near to the switch will cause it to close (if it has normally open contacts). A picture of a reed switch is shown below.
The switch contacts of a reed switch are sealed in an airtight glass tube.
This video demonstrates the operation of a reed switch.
Can't see the video? View on YouTube →
Reed switches are commonly found in alarm sensors that detect when a door or window is opened. An image of a reed switch used in an alarm system is shown below.
The reed switch alarm sensor is simply a reed switch packaged in a plastic case with an accompanying magnet packaged in a plastic case. The inside of the reed switch alarm sensor can be seen below.