Protection circuit assembly and method
AssigneeGeneral Electric Company
InventorsTamás Darányi, Lajos Csibi, Gábor Pap
Life of this patent
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Abstract
Single channel digital addressable lighting interface (DALI) systems can include a dedicated external power supply that operates in a constant voltage/constant current mode to meet requirements of the DALI bus. A lighting controller is powered from the DALI bus. In one embodiment of the inventive subject matter, a lighting system is provided that includes two or more control (e.g., DALI) buses and a multichannel power supply that can be used for powering a controller of the system with constant voltage and to power separate control buses with separate and constant current. In order to protect the controller and buses from overloads caused by miswiring or other erroneous conditions, a protection circuit assembly is provided.
Claims20
A lighting system comprising:
- plural protection circuits configured to be conductively coupled with a power supply that supplies current to plural light sources to power the light sources, the protection circuits configured to receive an input voltage from the power supply and to conduct an output voltage to separate control buses that are conductively coupled with drivers of the light sources to conduct control signals to the drivers of the light sources for control of operation of the light sources;
- a microcontroller configured to generate the control signals to control the operation of the light sources;
- and
- plural transceiving circuits configured to receive the control signals from the microcontroller and to conduct the control signals to different groups of the light sources via the separate control buses,
- wherein the protection circuits are separately connected to the separate control buses to conduct the output voltage from the power supply to the light sources, and wherein the protection circuits are configured to prevent an increase of voltage on a first control bus of the control buses from increasing voltage on a different, second control bus of the control buses.
A method comprising:
- receiving an input voltage from a power supply at plural protection circuits conductively coupled with the power supply to supply current to plural light sources to power the light sources;
- conducting an output voltage from the protection circuits to separate control buses that are conductively coupled with drivers of the light sources;
- communicating control signals from a microcontroller to the drivers of the light sources via plural transceiving circuits and the control buses for control of operation of the light sources, wherein the control signals are separately communicated to different groups of the light sources via the separate control buses for separate control of the different groups of the light sources;
- and
- preventing, with the protection circuits, an increase of voltage on a first control bus of the control buses from increasing voltage on a different, second control bus of the control buses.
A protection circuit assembly comprising:
- positive and negative voltage input connections configured to be conductively coupled with a power supply;
- positive and negative voltage output connections configured to be conductively coupled with separate control buses that are connected with light source drivers and light sources, the control buses configured to communicate control signals from a microcontroller to the light source drivers to control operation of the light sources;
- a first semiconductor switch having a gate coupled with the positive voltage input connection, a source coupled with the negative voltage input connection, and a drain coupled with the negative output voltage connection;
- a variable resistor thermally coupled with the first semiconductor switch and conductively coupled with the positive voltage input connection and the gate of the first semiconductor switch, the variable resistor having an electrical resistance that changes based on a change in temperature of the variable resistor,
- wherein a temperature of the first semiconductor switch increases in response to a voltage being injected into the negative voltage output connection that exceeds a second designated, non-zero injected voltage threshold, wherein the temperature increasing of the first semiconductor switch causes the temperature of the variable resistor to increase, and wherein the temperature increasing in the variable resistor increases the electrical resistance of the variable resistor to protect the controller from the voltage that is injected into the at least one of the output connections.
Dependencies are inferred from the claim text.