| 摘要 |
<p>SOLID STATE PROXIMITY SWITCH The specification discloses a magnetic proximity sensing apparatus for sensing ferro-magnetic objects. The sensor is especially well adapted for use with fluid cylinders having pistons formed from magnetically attracted material. The apparatus includes magnetic actuator means responsive to the proximity of the fluid cylinder piston or other ferro-magnetic object which closes a switch and enables electrical circuitry for controlling fluid valves or other apparatus. A reed switch mounted within a hollow, cylindrical, permanent magnet has a separate pole piece secured at one end of the reed switch. The proximity of a ferro-magnetic object changes the flux within the magnet, closing the reed switch. The circuitry is solid state and includes a silicon controlled rectifier acting as a gated switch for completing the circuit.</p> |
