Contactor drives having normally-on solid state switches
AssigneeHamilton Sundstrand Corporation
InventorThomas P. Joyce
Life of this patent
Estimating the term…
Abstract
A low-side contactor coil drive circuit can include an input line and a first solid state switch having a first switch base, a first switch collector, and a first switch emitter. The first switch collector can be connected to the input line and the first switch emitter is connected to ground. The circuit can include a second solid state switch having a second switch base, a second switch collector, and a second switch emitter. The second switch emitter can be connected to the input line in parallel with the first switch collector. The second switch collector can be connected to the first switch base. The circuit can include a third solid state switch having a third switch gate, a third switch source, and a third switch drain. The third switch drain can be connected to the second switch base.
Claims20
A low-side contactor coil drive circuit, comprising:
- an input line;
- a first solid state switch having a first switch base, a first switch collector, and a first switch emitter, wherein the first switch collector is connected to the input line and the first switch emitter is connected to ground;
- a second solid state switch having a second switch base, a second switch collector, and a second switch emitter, wherein the second switch emitter is connected to the input line in parallel with the first switch collector, wherein the second switch collector is connected to the first switch base;
- a third solid state switch having a third switch gate, a third switch source, and a third switch drain, wherein the third switch drain is connected to the second switch base;
- and
- a solid state switch controller connected to the third switch gate and configured to control a state of the third solid state switch;
- wherein the third solid state switch is normally on such that, if the solid state switch controller is unpowered, the third solid state switch is on, the solid state switch controller configured to pull the third switch gate low to turn the third solid state switch off.
A low-side contactor coil drive circuit, comprising:
- a plurality of solid state switches, at least one of the plurality of solid state switches configured to pass a load current;
- a normally-on solid state switch that is not capable of passing the load current, the normally-on solid state switch operatively connected to the plurality of solid state switches and configured to control a state of the plurality of solid state switches;
- and
- a solid state switch controller connected to the normally-on solid state switch and configured to control a state of the normally-on solid state switch;
- wherein, when the solid state switch controller is unpowered, the normally-on solid state switch is on;
- and
- wherein, when the solid state switch controller is powered, the solid state switch controller is configured to pull a gate of the normally-on solid state switch low to turn the normally-on solid state switch off.
A method comprising:
- providing an input from an input line to a plurality of solid state switches, at least one of the plurality of solid state switches configured to pass a load current;
- controlling, using a solid state switch controller, a state of a normally-on solid state switch, the normally-on solid state switch not capable of passing the load current, the normally-on solid state switch operatively connected to the plurality of solid state switches and controlling a state of the plurality of solid state switches;
- wherein, when the solid state switch controller is unpowered, the normally-on solid state switch is on;
- and
- wherein, when the solid state switch controller is powered, the solid state switch controller pulls a gate of the normally-on solid state switch low to turn the normally-on solid state switch off.
Dependencies are inferred from the claim text.