초록 ▼

Circuitry (100, 100') for determining actuator position includes four MOS transistors (T1-T4) connected to each side of a bi-directional motor (10). The current flowing through the motor (10) at any given time is proportional to voltages developed across the internal impedances of the transistors (T

Circuitry (100, 100') for determining actuator position includes four MOS transistors (T1-T4) connected to each side of a bi-directional motor (10). The current flowing through the motor (10) at any given time is proportional to voltages developed across the internal impedances of the transistors (T1-T4). The resulting motor voltages are amplified and high-pass filtered to remove any DC offsets due to the signal amplification. The conditioned motor voltages are then compared to one or more threshold voltages and passed through a one shot circuit (120) to provide detectable pulses for each motor commutation event. Circuitry (106,107) is provided for counting pulses provided by the one shot circuit (120) and, based on a desired motor position, for providing a number of digital control signals to a digital control circuit (104). Digital control circuit (104) is responsive to the number of digital control signals to control the gate voltages of the four transistors (T1-T4) to thereby control the position of the motor (10).

대표청구항 ▼

[ What is claimed is:] [1.] Circuitry for determining actuator position, comprising:a first drive device having a signal input adapted for connection to a supply voltage, an output adapted for connection to a first input of an actuator and a control input responsive to a first control signal for con

[ What is claimed is:] [1.] Circuitry for determining actuator position, comprising:a first drive device having a signal input adapted for connection to a supply voltage, an output adapted for connection to a first input of an actuator and a control input responsive to a first control signal for conducting a first load current through an internal resistance of said first drive device defined between said signal input and said output thereof, said first load current thereby defining a first load voltage at said output of said first drive device;a second drive device having a signal input adapted for connection to a second input of the actuator, an output adapted for connection to a reference potential and a control input responsive to a second control signal for conducting said first load current therethrough from said signal input to said output of said second drive device, said first load current defining a second load voltage at said signal input of said second drive device, said first and second drive devices adapted for driving the actuator in a first direction via said first load current;means responsive to one of said first and second load voltages for detecting voltage pulses associated therewith; andmeans responsive to said voltage pulses for controlling activation and deactivation of said first and second control signals.