US 10,873,329 B2Granted

High reliability AC load switching circuit

AssigneeIDEAL Industries Lighting LLC

InventorsYuequan Hu, Amruteshwar Hiremath, Kory A. Liszt

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Abstract

A high reliability AC load switching circuit is disclosed. In some embodiments, the AC load switching circuit includes a high-speed switch connected between the load and the voltage source, a cutoff switch connected between the load and the voltage source in parallel with the high-speed switch, and a level detector connected to the voltage source and to a control input of the high-speed switch. The high-speed switch may be a solid-state switch, for example, a TRIAC or a bidirectional switch, and the cutoff switch may be an electromechanical switch, for example, a relay. In some embodiments a snubber is connected in parallel with a solid-state switch. In some embodiments a microcontroller is connected to an electromechanical switch and the level detector. In some embodiments, both a first cutoff switch and a second cutoff switch are used.

Claims16

Dependent claims

A switching circuit to selectively connect a load to a voltage source, the switching circuit comprising:

a high-speed switch connected between the load and the voltage source;
a snubber connected in parallel with the high-speed switch;
a cutoff switch connected between the load and the voltage source in parallel with the high-speed switch;
a level detector and control circuit connected to the voltage source and to a control input of the high-speed switch, wherein the control input is further connected to a portion of the switching circuit that is between the load and an output of the high-speed switch and between the load and an output of the cutoff switch;
and
a controller comprising a first enabling input connected to the level detector and control circuit and a second enabling input connected to the cutoff switch, the controller further comprising a processor and memory storing at least one of firmware and software that is executable such that:
the first enabling input is activated in response to a powering on signal received from the controller and the level detector and control circuit turns on the high-speed switch at a zero crossing of the voltage source, and the second enabling input is activated independent of the operation of the high-speed switch after the high-speed switch is turned on to turn on the cutoff switch, the high-speed switch remaining turned on after the cutoff switch is turned on.

4 more elements

A method of selectively connecting a load to an AC voltage through a switching circuit comprising a controller comprising a first enabling input connected to a level detector and control circuit and a second enabling input connected to a cutoff switch, the controller further comprising a processor and memory storing at least one of firmware and software, the method comprising:

activating the first enabling input from the controller in response to a powering on signal received from the controller to thereby enable the level detector and control circuit to turn on a solid-state switch between the AC voltage and the load at zero-crossing of the AC voltage;
suppressing voltage spikes and/or dampening ringing to prevent misfiring of the solid-state switch using a snubber connected in parallel with the solid-state switch;
and
activating a second enabling input from the controller to close a first electromechanical switch connected in parallel with the solid-state switch independent of the operation of the solid-state switch after the turning on of the solid-state switch to turn on the cutoff switch, maintaining the solid-state switch turned on after the cutoff switch is turned on using a control input of the solid-state switch that is connected between the load and an output of the solid-state switch and between the load and an output of the cutoff switch.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 16/385,020Filed 16 Apr 2019 · continuation
Priority: 24 Jun 2016
Published: US 2019/0245537 A18 Aug 2019
Granted: 22 Dec 2020
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

H03K 17/68
The devices being bipolar transistors: specially adapted for switching AC currents or voltages
H03K 17/72
By the use, as active elements, of semiconductor devices: having more than two PN junctions; having more than three electrodes; having more than…
H02H 9/002
Limiting speed of change of electric quantities, e.g. soft switching on or off: limiting inrush current on switching on of inductive loads…
H03K 2217/0009
Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00: aC switches, i.e.…

Family

Application15/191,972Parent of this continuation · filed 24 Jun 2016
US 2019/0245537 A1Pre-grant publication · published 8 Aug 2019
US 2017/0373684 A1Published application
US 10,873,329 B2This patent

From the US filing history. Foreign family members aren’t listed.

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