Pulse width modulation control of solenoid motor

摘要

A drive mechanism configured to drive a thermally isolated actuator between two positions. The drive mechanism includes a rotary actuated motor configured to rotatably drive a motor member, and a drive member coupled to the motor member and having a drive arm configured to responsively move from a first position to a second position upon rotation of the motor member. An actuator is responsive to movement of the drive arm moved from the first position to the second position. A drive circuit is configured to generate a pulse width modulated (PWM) drive signal configured to controllably drive the motor, the PWM drive signal having a first duty cycle configured to advance the drive arm from the first position, and having a second duty cycle different than the first duty cycle as the drive arm approaches the second position. The drive signal may be removed before the drive arm engages a hard stop. The drive mechanism may comprise at least one sensor configured to determine a position of the drive arm proximate the first position and proximate the second position. The actuator is thermally isolated from the drive arm in both the first position and the second position.

主权项

1. A device, comprising:
a rotary actuated motor configured to rotatably drive a motor member; a drive member coupled to the motor member and having a drive arm configured to responsively move from a first position to a second position upon rotation of the motor member; a first sensor disposed proximate the first position; a second sensor disposed proximate the second position; and a drive circuit configured to generate a pulse width modulated (PWM) drive signal to controllably drive the motor, the PWM drive signal having (i) a first duty cycle configured to advance the drive arm from the first position to a first intermediate position between the first position and the second position, the first intermediate position corresponding to an outer edge of a sensing range of the first sensor, (ii) a second duty cycle configured to advance the drive arm from the first intermediate position to a second intermediate position between the first intermediate position and the second position, the second intermediate position corresponding to an outer edge of a sensing range of the second sensor, the second duty cycle different than the first duty cycle, and (iii) a third duty cycle configured to be used as the drive arm approaches the second position from the second intermediate position; wherein the drive circuit is configured to gradually increase the first duty cycle over multiple increments to gradually increase a force delivered to the drive member; and wherein the drive circuit is configured to establish the first, second, and third duty cycles as a function of at least one output from the first and second sensors.