Back to results
US 8,476,845 B2Granted
Brightness control for lighting fixtures
AssigneeCRS Electronics
InventorScott Riesebosch
Life of this patent
Estimating the term…
Abstract
A brightness controller determines a lowest dimmer setpoint and an average power to a light source at the lowest dimmer setpoint. An average power supplied to the light source is set based on a setting of the dimmer relative to the average power at the lowest dimmer setpoint.
Claims13
A method of adjusting brightness of a light source controlled by a dimmer, the method comprising the steps of:
- determining a lowest dimmer setpoint and an average power to the light source at the lowest dimmer setpoint, wherein determining the lowest dimmer setpoint comprises:
- (i) monitoring a power signal supplied to the light source;
- (ii) identifying, based on a characteristic of the power signal, a lowest dimmer setpoint and a current dimmer setting;
- (iii) setting the brightness of the light source to a pre-determined minimum level based at least in part on the lowest dimmer setpoint;
- and
- (iv) adjusting the brightness of the light source according to a difference between the current dimmer setting and the lowest dimmer setpoint;
- and
- setting an average power supplied to the light source based on a setting of the dimmer relative to the average power at the lowest dimmer setpoint.
5 more elements
A brightness controller for adjusting a brightness of a light source controlled by a dimmer, the brightness controller comprising:
- a dimmer-level estimator for determining a current and a lowest dimmer level, wherein the dimmer-level estimator comprises:
- (i) a duty-cycle estimator for estimating a current duty cycle of a power signal supplied to the light source;
- (ii) a storage device for storing a minimum duty cycle of the power signal estimated by the duty-cycle estimator, and associating the minimum duty cycle with a lowest dimmer level;
- (iii) a comparator for comparing the current duty cycle with the stored minimum duty cycle, and updating the stored minimum duty cycle if the current duty cycle is smaller than the stored minimum duty cycle;
- and
- (iv) a dimmer-level calculator for determining a current dimmer level corresponding to a difference between the current duty cycle and the stored minimum duty cycle;
- and
- a driver for adjusting the brightness of the light source according to the current dimmer level and average power supplied to the light source at the lowest dimmer level.
5 more elements
Dependencies are inferred from the claim text.