|MDC magnetic reed switches consist of
four basic components: a glass capsule, a gas filler (the atmosphere inside the glass
capsule), electrical contacts and two ferromagnetic reeds.
The reeds are hermetically sealed into the glass capsule in a cantilever fashion so that
the ends align and overlap, while maintaining a small gap between them. The
floating end of each reed will assume opposite magnetic polarity when brought
into the proximity of a magnetic field. When the magnetic flux density is sufficient, the
attraction force of the opposing magnetic poles will overcome the reed stiffness
causing them to flex towards each other and make electrical contact. Since these
switches have no mechanical parts to wear out this operation can be repeated millions
The characteristic life expectancy of these switches is rated at 100 million cycles,
provided electrical ratings are not exceeded.
Contacts normally open, 110-120VAC, 0.5 amperes and 10 watts maximum. MDC
reed switch position indicators will operate at temperatures ranging from (-) 40°C to