| 摘要 |
<p>A solid state noncontacting mechanically actuated keyboard switch and interconnecting network for switch arrays. The switch provides a high degree of transformer balance and when implementing a N-Key rollover circuit employing the differential transformer type switch, diodes for isolation purposes are not required. The basic switch is a balanced or differential transformer element with a movable magnetic core (14), or shorted turn, actuator which is inserted through one-half of the transformer element, one primary-secondary pair (2, 6) causing the transformer to change from a balanced or "off" state to an unbalanced or "on" state. The single turn coils that make up the differential transformer element lie in a plane, and in one embodiment of this invention the primary coils (22) and their interconnecting network are printed on one side of a double printed circuit board (25), and the secondary coils (23) and their interconnecting network are printed in proper alignment on the opposite side. A hole is provided through the printed circuit board for each transformer element for insertion of a magnetic actuator (28). Included is a two dimensional X-Y switch matrix for facilitating electronic scanning of the keyboard for implementing encoding multikey rollover, etc. techniques. </p> |
