US 10,756,662 B2Granted

Motor control device

AssigneeLutron Technology Company LLC

InventorsJames P. Steiner, Dinesh Sundara Moorthy

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Abstract

A load control device may control power delivered from a power source, such as an alternating-current (AC) power source, to at least two electrical loads, such as a lighting load and a motor load. The load control device may include multiple load control circuit, such as a dimmer circuit and a motor drive circuit, for controlling the power delivered to the lighting load and the motor load, respectively. The load control device may adjust the rotational speed of the motor load in a manner so as to minimize acoustic noise generated by the load control device and reduce the amount of time required to adjust the rotational speed of the motor load. The load control device may remain powered when one of the electrical loads (e.g., the lighting load) has been removed (e.g., electrically disconnected or uninstalled) and/or has failed in an open state (has “burnt out” or “blown out”).

Claims20

Dependent claims

A load control device for controlling power delivered from an alternating-current (AC) power source to a motor load, the load control device comprising:

first and second capacitors;
first and second controllable switching circuits coupled in series with the first and second capacitors, respectively;
a control circuit configured to control the first controllable switching circuit to electrically couple the first capacitor in series between the AC power source and the motor load to cause the motor load to rotate at a first rotational speed, the control circuit configured to control the second controllable switching circuit to electrically couple the second capacitor in series between the AC power source and the motor load to cause the motor load to rotate at a second rotational speed;
and
first and second resistors configured to be coupled in parallel with the first and second capacitors, respectively, when the respective capacitor is not electrically coupled in series between the AC power source and the motor load;
wherein, when the control circuit receives a command to change the motor load from the first rotational speed to the second rotational speed, the control circuit is configured to:
control the first controllable switching circuit to disconnect the first capacitor from the series electrical connection between the AC power source and the motor load at approximately a first zero-crossing of the AC power source;
wait for a wait time period to allow the first capacitor to discharge through the first resistor;
and
subsequently control the second controllable switching circuit to connect the second capacitor in series electrical connection between the AC power source and the motor load at approximately a second zero-crossing of the AC power source;
wherein the first and second resistors are not coupled in parallel with the first and second capacitors, respectively, when the respective capacitor is electrically coupled in series between the AC power source and the motor load.

8 more elements

A method of controlling power delivered from an alternating-current (AC) power source to a motor load, the method comprising:

controlling a first controllable switching circuit to electrically couple a first capacitor in series between the AC power source and the motor load to cause the motor load to rotate at a first rotational speed;
controlling a second controllable switching circuit to electrically couple a second capacitor in series between the AC power source and the motor load to cause the motor load to rotate at a second rotational speed;
and
changing the motor load from the first rotational speed to the second rotational speed by controlling the first controllable switching circuit to disconnect the first capacitor from the series electrical connection between the AC power source and the motor load at approximately a first zero-crossing of the AC power source, connecting a first resistor in parallel electrical connection with the first capacitor when the first capacitor is not connected in series electrical between the AC power source and the motor load, waiting for a wait time period to allow the first capacitor to discharge through the first resistor, and subsequently controlling the second controllable switching circuit to connect the second capacitor in series electrical connection between the AC power source and the motor load at approximately a second zero-crossing of the AC power source;
wherein the first resistor is not coupled in parallel with the first capacitor when the first capacitor is electrically coupled in series between the AC power source and the motor load.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/003,864Filed 8 Jun 2018 · us provisional application
Priority: 9 Jun 2017
Published: US 2019/0013758 A110 Jan 2019
Granted: 25 Aug 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification14 codes

H02P 25/04
Characterised by the kind of motor: single phase motors, e.g. capacitor motors
F21V 33/0096
Ventilating systems: fans, e.g. ceiling fans
H01H 47/02
Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide…:…
H02P 1/24
For starting dynamo-electric motors or dynamo-electric converters: for starting an individual AC commutator motor