Miniature electronic switch compensated for temperature hysteresis - uses damping as well as ferromagnet elements to alter Q value of oscillator

摘要

The miniature electronic switch has a depressable button head whose shaft carries a ferromagnetic element that alters the Q of the resonant circuit of an oscillator. The switching signal is derived in the usual way from the oscillator output. To compensate for temperature hysteresis and to keep the switching characteristics constant, the shaft of the button not only has the ferromagnetic element (39) to increase the Q but also a damping element (38) above it. Both elements pass axially through the resonant circuit's tubular coils (31, 33). The damping element is made of e.g. iron, copper or aluminium, or of a metal alloy.