CONTROL DEVICE HAVING A NIGHT LIGHT
A control device has a night light that allows the control device to be easily found when the control device is located in a dark space. The control device comprises a low-power night light circuit having an LED characterized by a normal current range. The night light circuit conducts an LED current through the LED in a first mode to illuminate the LED to a first level to provide a night light, where the LED current has a magnitude below the normal current range, such that the night light may be provided in a battery-powered remote control that has an acceptable battery lifetime. The night light circuit is configured to operate in a second mode to illuminate the LED to a second level greater than the first level to provide feedback. The LED current in the second mode has a magnitude within the normal current range of the LED.
1 . A control device for use in a load control system for controlling an electrical load receiving power from a power source, the control device comprising:
a visual indicator;
an indicator circuit comprising an LED for illuminating the visual indicator, the indicator circuit operable to conduct an LED current through the LED to illuminate the LED, the LED having a normal operating current range; and
a controller coupled to the indicator circuit, the controller configured to control the indicator circuit in a first mode to illuminate the LED to a first level to provide a night light, the LED current in the first mode having a magnitude below the normal operating current range;
wherein the controller is configured to control the indicator circuit in a second mode to illuminate the LED to a second level greater than the first level to provide feedback to a user of the control device, the LED current in the second mode having a magnitude within the normal operating current range of the LED.
2 . The control device of claim 1 , further comprising:
an actuator, the controller responsive to actuations of the actuator.
3 . The control device of claim 2 , wherein the visual indicator is provided in a front surface of the actuator.
4 . The control device of claim 3 , further comprising:
a light pipe for conducting the light from the LED to the visual indicator at the front surface of the actuator;
wherein the light pipe is cylindrical and has a textured, circular front surface having a convex shape extending outwards from the front surface of the actuator.
5 . The control device of claim 4 , wherein the front surface of the light pipe has a stepped profile formed by a plurality of concentric circular steps.
6 . The control device of claim 4 , wherein the front surface of the light pipe has steps formed in a continuous helix shape.
7 . The control device of claim 2 , further comprising:
an enclosure portion in which the actuator is provided;
wherein the visual indicator is located in the enclosure portion adjacent the actuator.
8 . The control device of claim 2 , further comprising:
a wireless transmitter operatively coupled to the controller;
wherein the controller is operable to transmit a digital message in response to actuations of the actuator.
9 . The control device of claim 2 , wherein the controller is configured to pulse-width modulate the LED current to blink the visual indicator to provide feedback when the actuator is actuated.
10 . The control device of claim 1 , further comprising:
a battery for producing a battery voltage to power the controller and the indicator circuit.
11 . The control device of claim 10 , wherein the LED current conducted through the LED by the indicator circuit in the first mode has a constant magnitude.
12 . The control device of claim 11 , wherein the controller is coupled to the indicator circuit for adjusting the constant magnitude of the LED current.
13 . The control device of claim 12 , wherein the controller is further configured to pulse-width modulate the LED current.
14 . The control device of claim 13 , wherein the indicator circuit comprises an op amp constant current source circuit.
15 . The control device of claim 13 , wherein the indicator circuit comprises a multivibrator circuit in which the LED is electrically connected.
16 . The control device of claim 10 , wherein the control device comprises a battery-powered remote control.
17 . The control device of claim 1 , wherein the LED current has a constant magnitude of a few μA in the first mode, and has a peak magnitude of approximately 2 mA in the second mode.
18 . The control device of claim 17 , wherein the LED current has a constant magnitude of approximately 1.5 μA or less in the first mode.
19 . The control device of claim 1 , wherein the controller is configured to enter a sleep mode when the LED is illuminated to the first level in the first mode.
20 . The control device of claim 1 , wherein the controller is configured to pulse-width modulate the LED current in the second mode to cause the LED to blink to provide feedback to the user.