Abstract: A system of sensing elevator car position is presented that dynamically compensates for problems due to frictional slippage of its mechanical connection and/or building settlement. The system comprises an elevator car within an elevator hoistway. An encoder is mounted within the elevator hoistway and mechanically connected to the elevator car. The mechanical connection drives the encoder which generates data indicative of the position of the elevator car. Either one of a position sensor and a position sensor actuator is mounted to a landing of the hoistway. The other one of the position sensor and position sensor actuator is mounted to the elevator car. The position sensor generates data indicative of the elevator car floor reaching a predetermined distance from the elevator landing when actuated by the position sensor actuator. An elevator position controller receives the data generated by both the position sensor and the encoder.

Abstract: A system of sensing elevator car position is presented that dynamically compensates for problems due to frictional slippage of its mechanical connection and/or building settlement. The system comprises an elevator car within an elevator hoistway. An encoder is mounted within the elevator hoistway and mechanically connected to the elevator car. The mechanical connection drives the encoder which generates data indicative of the position of the elevator car. Either one of a position sensor and a position sensor actuator is mounted to a landing of the hoistway. The other one of the position sensor and position sensor actuator is mounted to the elevator car. The position sensor generates data indicative of the elevator car floor reaching a predetermined distance from the elevator landing when actuated by the position sensor actuator. An elevator position controller receives the data generated by both the position sensor and the encoder.

Abstract: A telephone transmit circuit is connected through a resistor to a junction at which a telephone line interface circuit is connected, a transhybrid cancellation circuit is connected to the transmit circuit and includes a high frequency shunt matching network having capacitive and inductive components and a low frequency matching circuit which comprises a lead lag network having capacitive components, the output of the transhybrid circuit being connected to a summing junction at the input of a telephone receiver. The other input of the summing network is connected between the resistor and the interface circuit, whereby a portion of the transmit signal is fed back out of phase to the receive amplifier so as to cancel out undesirable side tones, across a predetermined frequency range.