Abstract: An emergency stop circuit for an elevator drive includes an emergency stop control (7) that selectively varies the current flowing in a field winding (4) of a direct current drive motor (M). During an emergency stop, the motor (M) operates as a generator and has an armature winding (1) loaded with a braking resistor (9) to apply a voltage, depending on the direction of movement of the elevator car, either by a first switch (10) and a second switch (11), or by a third switch (12) and a fourth switch (13). The switches (10, 11, 12, 13) are connected as an H-bridge between the windings (1, 4) and are controlled by the emergency stop control (7) depending on the deceleration required by the elevator car, for example by pulse operation depending based upon a preset deceleration value and a measured deceleration value from a deceleration sensor (14) mounted on the car.

Abstract: An apparatus for controlling an emergency stop of an elevator car 11 is connected in an elevator system 10 including a drive motor 15 coupled to the car, a drive control 18 connected between the drive motor and an AC electrical power source 17 for operating the drive motor and an elevator control 19 connected to the drive control for controlling starting, running and stopping of the elevator car. A controlled emergency stop circuit 21 has a battery supply 28 connected to receive and store electrical power from the power source 17 and is connected to provide electrical power to the elevator control 19. A normally open switch 33,34,36,37 is connected between the battery supply 28 and the drive control 18. A controller is connected to the switch and receives a power failure signal representing a loss of electrical power at the drive control 18.

Abstract: An apparatus and a method for controlling an elevator brake assembly (1) includes a control circuit (CM) for selectively connecting an electrical power supply (28) to a brake armature coil (9) to move an armature plate (4) between a brake actuated rest position against a brake friction lining (5) and a brake released hold position adjacent a brake housing (2). The control circuit (CM) applies a first voltage to the coil (9) to move the armature plate (4) against a force applied by a spring (3) from the rest position to the hold position in response to a signal on a brake pick signal line (BP). The control circuit (CM) applies a second voltage to the coil (9) to control the movement of the armature plate (4) by the spring (3) from the hold position to the rest position in accordance with a predetermined velocity versus distance curve to achieve minimum impact on the lining (5) at the rest position.