Patent ID: 11863103
Assignee: LUTRON TECHNOLOGY COMPANY LLC
Field: Civil engineering (Other fields)
Classification: CPC E  H  Y | IPC E  H

Claim 7:
8. The motor drive unit of claim 7, wherein the stall prevention circuit comprises:
a capacitor coupled to the drive signal through a resistor for producing a DC voltage across the capacitor;
an edge detect circuit configured to receive the sensor signal and generate an edge detect signal that indicates edges of the sensor signal;
a first comparator having a positive input coupled to receive a first reference voltage, a negative input coupled to receive the edge detect signal, and an output configured to discharge the capacitor at one or more of the edges of the sensor signal;
a second comparator having a positive input coupled to receive a second reference voltage, a negative input coupled to receive the DC voltage across the capacitor, and an output configured to control the magnitude of the enable signal;
wherein the first comparator is configured to control the DC voltage across the capacitor to approximately zero volts when the rotational sensing circuit is generating the sensor signal, the second comparator configured to control the enable signal to disable the motor drive circuit when the rotational sensing circuit is not generating the sensor signal and the magnitude of the DC voltage across the capacitor exceeds the second reference voltage.