Load control device for controlling a driver for a lighting load
A load control device is configured to generate a control signal having a desired magnitude for controlling a load regulation device adapted to control the power delivered to an electrical load. The load control device may comprise a control terminal arranged to provide the control signal to the load regulation device, a communication circuit for generating the control signal, and a control circuit configured to generate an output signal that is provided to the communication circuit. The communication circuit may be characterized by non-linear operation. The control circuit may adjust the magnitude of the output signal in response to the difference between the magnitude of the control signal and the desired magnitude to adjust the magnitude of the control signal towards the desired magnitude. The control circuit may also be configured to determine if an incompatible load regulation device is coupled to the load control device.
1. A load control device for controlling a load regulation device adapted to control power delivered from an AC power source to an electrical load, the load control device comprising:
a control terminal adapted to be coupled to the load regulation device for providing a control signal to the load regulation device, the control signal having a magnitude indicating a target amount of power to be delivered to the electrical load;
a communication circuit coupled to the control terminal for generating the control signal; and
a control circuit configured to:
prior to the communication circuit generating the control signal at the control terminal, receive a feedback signal indicating a magnitude of a voltage at the control terminal;
monitor the magnitude of the voltage at the control terminal to determine if the load regulation device is generating a link supply voltage;
based on the determinization, enter a normal mode or a fault mode; and
in the normal mode, provide an output signal to the communication circuit to cause the communication circuit to control the magnitude of the control signal in response to a magnitude of the output signal.
2. The load control device of claim 1 , wherein, in the fault mode, the control circuit is configured to determine that the load regulation device is incompatible with the communication circuit of the load control device.
3. The load control device of claim 1 , wherein the communication circuit comprises a current sink circuit arranged to sink current through the control terminal.
4. The load control device of claim 1 , wherein the control circuit is configured to monitor the magnitude of the voltage at the control terminal to determine if the link supply voltage is present at the control terminal in order to determine if the load regulation device is compatible or incompatible with the communication circuit of the load control device.
5. The load control device of claim 1 , wherein the control circuit is configured to determine that the load regulation device is compatible with the communication circuit and operate in the normal mode if the link supply voltage is present at the control terminal, and to determine that the load regulation device is incompatible with the communication circuit and operate in the fault mode if the link supply voltage is not present at the control terminal.
6. The load control device of claim 1 , wherein the control circuit is configured to compare the voltage at the control terminal to a predetermined threshold to determine if the link supply voltage is present at the control terminal in order to determine if the load regulation device is compatible or incompatible with the communication circuit of the load control device.
7. The load control device of claim 6 , wherein the control circuit is configured to determine that the load regulation device is compatible with the communication circuit if the voltage at the control terminal exceeds the predetermined threshold.
8. The load control device of claim 1 , wherein the control circuit is configured to monitor the magnitude of the voltage at the control terminal to determine if the load regulation device is generating the link supply voltage when the load control device is powered up.
9. The load control device of claim 1 , wherein the control circuit is configured to operate in the normal mode if the control circuit determines that the load regulation device is generating the link supply voltage.
10. The load control device of claim 1 , wherein the control circuit is configured to operate in the fault mode if the control circuit determines that the load regulation device is not generating the link supply voltage.
11. The load control device of claim 1 , wherein the control circuit is configured to operate as a dimmer switch in the normal mode and an electronic switch in the fault mode.
12. The load control device of claim 11 , wherein the electrical load comprises a lighting load, the control circuit configured to fade the lighting load on and off in the normal mode by gradually adjusting an intensity of the lighting load on and off over a fade period.
13. The load control device of claim 12 , wherein the control circuit is configured to operate as the electronic switch by turning the lighting load on and off in the fault mode without the use of the fade period.
14. The load control device of claim 1 , wherein the control circuit is configured to blink a visual indicator in the fault mode.
15. The load control device of claim 14 , wherein the control circuit is configured to blink the visual indicator when the load control device powers up and the control circuit determines that the load regulation device is not generating the link supply voltage.
16. The load control device of claim 14 , further comprising:
an intensity adjustment actuator for receiving a user input;
wherein the control circuit is configured to determine a desired amount of power to be delivered to the electrical load in response to actuations of the intensity adjustment actuator, and blink the visual indicator when the intensity adjustment actuator is actuated in the fault mode.
17. The load control device of claim 1 , wherein the control circuit is configured to adjust the magnitude of the control signal to adjust the amount of power delivered to the electrical load in the normal mode.
18. The load control device of claim 1 , wherein the control circuit is further configured to monitor the magnitude of the voltage at the control terminal to determine if a miswire condition exists at the control terminal.
19. The load control device of claim 1 , wherein the control circuit is configured to wait for a delay period after the load control device is powered up before starting to monitor the magnitude of the voltage at the control terminal to determine if the load regulation device is generating the link supply voltage.
20. A load control device for controlling a load regulation device adapted to control power delivered from an AC power source to an electrical load, the load control device comprising:
a control terminal adapted to be coupled to the load regulation device for providing a control signal to the load regulation device, the control signal having a magnitude indicating a target amount of power to be delivered to the electrical load;
a communication circuit coupled to the control terminal for generating the control signal; and
a control circuit configured to:
receive a feedback signal indicating a magnitude of a voltage at the control terminal;
monitor the magnitude of the voltage at the control terminal to determine if the load regulation device is generating a link supply voltage;
based on the determinization, enter a normal mode or a fault mode; and
in the normal mode, provide an output signal to the communication circuit to cause the communication circuit to control the magnitude of the control signal in response to a magnitude of the output signal.