Transistorized elevator control button
AssigneeOtis Elevator Company
InventorKenneth R. Brooks
Life of this patent
Estimating the term…
Abstract
A switch is closed to generate a short duration pulse. The pulse activates a semiconductor switch which powers an indicator lamp and generates a D.C. control signal on a single conductor. A latching unit responds to the D.C. signal on the conductor to latch the switch in the activated state. A reset signal consisting of half wave pulses is transmitted over the conductor. These pulses charge a capacitor coupled to the switch input to substantially the peak voltage of the half wave pulses, which deactivates the switch. The capacitor holds a voltage of sufficient level to maintain the switch in the deactivated state until the latch unit is deactivated when transmission of the reset signal stops.
Claims10
Apparatus adapted for connection to a single conductor, for generating a control signal thereon from a latched, activated state, and resetable from said state in response to a reset signal selectively applied to the conductor, said apparatus comprising,
- a switch selectively activated for generating the control signal upon the conductor,
- latch means, in circuit with the conductor and said switch, for supplying a signal to maintain said switch in said activated state in response to said control signal, said latch means characterized in that it also generates said maintaining signal in response to said reset signal,
- reset means for generating a signal to deactivate said switch, in response to the reset signal, as long as said latch means supplies said maintaining signal to said switch, in response to the reset signal,
- whereby both said switch and said latch means are returned to normally deactivated states when the reset signal is removed from said conductor.
A solid-state switch for elevator control systems of the type including a first conductor for carrying selectively applied elevator control and switch reset signals between an elevator control center and said switch, and a second conductor supplying a direct current power to said switch from the control center, comprising,
- means for generating a nonrepetitive pulse,
- an indicator device adapted to be powered from the D.C. voltage,
- control signal generation means, activated by said pulse, for generating an elevator call signal on the first conductor and activating said indicator from the D.C. voltage supplied on the second conductor,
- latch means for maintaining activation of said generation means following said pulse in response to said call signal or the switch reset signal, and
- reset means for deactivating said generation means in response to the switch reset signal and for maintaining deactivation following the application of the reset signal.
Dependencies are inferred from the claim text.