Method of controlling a motorized window treatment

A method of controlling a motorized window treatment in response to a command, the motorized window treatment comprises a motor selectively driven by a bus voltage, the method comprising the steps of:

• generating a pulse-width modulated signal from the bus voltage, the pulse-width modulated signal characterized by a duty cycle;
• driving the motor with the pulse-width modulated signal in response to the command;
• monitoring the magnitude of the bus voltage;
• comparing the magnitude of the bus voltage to a first voltage threshold;
• and
• decreasing the duty cycle of the pulse-width modulated signal driving the motor if the magnitude of the bus voltage has dropped below the first voltage threshold;
• comparing the magnitude of the bus voltage to a second voltage threshold after the step of reducing the duty cycle of the pulse-width modulated signal;
• and increasing the duty cycle of the pulse-width modulated signal driving the motor if the magnitude of the bus voltage has risen above the second voltage threshold.

An electronic drive unit for controlling the position of a motorized window treatment comprising:

• a motor coupled to the motorized window treatment for adjusting the position the motorized window treatment;
• a motor drive circuit coupled to the motor for driving the motor from a bus voltage;
• a controller coupled to the motor drive circuit operable to drive the motor drive circuit so as to control the rotation of the motor to control the motorized window treatment in response to a command;
• and
• a bus voltage monitor circuit coupled to the controller for providing a control signal representative of a magnitude of the bus voltage to the controller;
• wherein the controller is operable to compare the magnitude of the bus voltage to a first voltage threshold, to control the motor drive circuit to decrease the amount of current supplied to the motor if the bus voltage has dropped below the first voltage threshold, to subsequently compare the magnitude of the bus voltage to a second voltage threshold, and to control the motor drive circuit to increase the amount of current supplied to the motor if the bus voltage has risen above the second voltage threshold.

A system for delivering a transitory duration of high power from a power source to an electrical load without collapsing a supply voltage, the system comprising:

• a first power supply for generating a bus voltage from a source voltage of the power source;
• a second power supply for generating the supply voltage from the bus voltage;
• a drive circuit receiving the bus voltage and adapted to control the amount of current delivered to the electrical load;
• and
• a controller powered by the supply voltage and coupled to the drive circuit for controlling the amount of current delivered to the electrical load and responsive to the magnitude of the bus voltage, the controller operable to compare the magnitude of the bus voltage to a first voltage threshold, to control the drive circuit to decrease the amount of current supplied to the electrical load if the bus voltage has dropped below the first voltage threshold, to subsequently compare the magnitude of the bus voltage to a second voltage threshold, and to control the drive circuit to increase the amount of current supplied to the electrical load if the bus voltage has risen above the second voltage threshold.