Standex Electronics' GR150

The GR150 is a normally open switch that closes when properly placed near a magnetic source. It consists of two magnetic members hermetically sealed in a glass capsule, switching takes place in an inert environment. The small size and high magnetic sensitivity makes the GR150 ideal for use in hearing aids, heart pacemakers, pill cams, cell phones and similar electronic devices. Hearing aids use the switch to automatically switch the hearing aid to a mode (T-coil) that gives better performance when the end customer is using a telephone (which has a low-grade ceramic magnet located in the handset). The smaller size of the GR150 allows engineers more flexibility in the mechanical design of miniature electronic devices. The availability of very tight ampere turn (AT) ranges allow the design engineer better control of the magnetic variables in his design. The magnetic sensitivity of reed switches is measured in Ampere Turns (AT) in a specified test coil. Unlike some other magnetic sensors which have a power drain while in their off state, the GR150 consumes no power in the off state. The GR150 is just 3.7 mm in length - the next largest magnetic reed switch available is approximately 10 percent longer. Designs incorporating subminiature reed switches benefit substantially from a 10 percent reduction in switch body length. Typical subminiature magnetic reed switches have a substantial spread in ampere turns (AT). As produced subminiature reed switches normally have a sensitivity range of 2 to 30AT. The unique GR150 manufacturing process is capable of an 80% process yield in a narrow 2AT band. This would mean that our manufacturing process is capable of giving us an 80 percent yield in an AT range of 3 / 4AT.

For more infromationwww.standexelectronics.com/products/pdfs/GR150.pdf