What can reed switches be used for?
Reed switches actuated by magnets are commonly used in mechanical systems as proximity sensors. Examples are door and window sensors in burglar alarm systems and tamperproofing methods. Reed switches have been used in laptops to put the laptop into sleep/hibernation mode when the lid is closed.
How many amps can a reed switch handle?
If one is just switching a low-current signal, this is generally not a concern, as almost any reed switch can handle at least 100mA.
Are reed switches fragile?
SINCE REED SWITCHES are made of fragile glass, extreme care needs to be taken when handling them. If not discovered, damaged sensors may result in undetected break-ins.
Can a reed switch become magnetized?
First, the magnet interaction effects the reed switch when a permanent magnet (as shown below) is brought into the proximity of the switch. What happens is the individual reeds become magnetized with the attractive magnetic polarity as shown.
Are reed switches polarity sensitive?
Form B type Normally closed and Form E type Latching reed contacts are polarity sensitive.
How much voltage can a reed switch handle?
Some smaller evacuated reeds can stand off up to 4000 Volts DC. Small pressurized reed switches generally withstand 250 to 600 Volts DC.
How fast can a reed switch operate?
One generally sees one or two bounces occurring over a 50 ms to 100 ms period. Most small Reed Switches operate, including bounce, in the range of 100 ms to 500 ms.
What are the advantages of reed switches?
Since the contacts of the Reed Switch are sealed away from the atmosphere, they are protected against atmospheric corrosion. The hermetic sealing of a reed switch makes them suitable for use in explosive atmospheres where tiny sparks from conventional switches would constitute a hazard.
How to interface reed switch with Arduino?
To interface reed switch with Arduino we need to build a voltage divider circuit as shown in the figure below. Voltage is +5V when the switch is open and 0V when the switch is closed. We are using a normally open reed switch in this project. Switch is closed in the presence of magnetic field and it is open in the absence of magnetic field.
Where can I find a reed switch?
Reed switches are everywhere. Just about everywhere you go, you’ll find a Reed Switch nearby that’s quietly doing its job. Reed switches are everywhere. Reed switch was invented in 1936 by Walter B. Ellwood in the Bell Telephone Labs.
What is an RF reed switch?
Reed switch also called reed relay, is a low current magnetic switch with a concealed pair of contacts that close and open in response to magnetic field near it. The contacts are concealed inside a glass tube and its ends terminated out of the glass tube for external connection.