Light-sensing, light fixture control system

• US 4,587,459 A
• Filed: 12/27/1983
• Issued: 05/06/1986
• Est. Priority Date: 12/27/1983
• Status: Expired due to Term

• Current Assignee: Frederick H. Blake
• Original Assignee: Frederick H. Blake
• Inventors: Blake, Frederick H.
• Primary Examiner(s): Dixon, Harold
• Application Number:
  US06/565,582
• Time in Patent Office: 861 Days
• Field of Search: 315/158, 315/307, 315/175, 315/320
• US Class Current: 315/158
• CPC Class Codes: H05B 39/042 by measuring the incident light
• CPC Class Codes: Y02B 20/00 Energy efficient lighting technologies, e.g. halogen lamps or gas discharge lamps

Abstract

Disclosed is a lighting control system which switches a light fixture on or off, depending upon the amount of ambient light. The control system particularly allows natural light from the sun to be used to the greatest extent possible to supplement electric lighting and vice versa. The system incorporates a photocell light sensor, control circuit, power source, and switching unit. The photocell light sensor is mounted in optical communication with a source of ambient light. In response to the detection by the sensor of a predetermined light level, the control circuit activates the switching unit which is interposed in a circuit furnishing electrical power to a light fixture. The power source supplies power to the control circuit at a voltage of no greater than 20 volts at a current of no greater than 8 amps.

Claims

1. A light-sensing, light fixture control system that can be used in conjunction with a conventional high-voltage lighting system;

having a conventional high-voltage power source system;

said control system comprised of;

a light sensor mounted in optical communication with the ambient light near a light fixture;

a switch interposed in a circuit furnishing electrical power to the light fixture;

a power source for supplying voltage of no greater than 20 volts at an amperage of no greater than 8 amperes to a control circuit;

said power source located immediately adjacent a conventional power source for electrical attachment thereto; and

a control circuit electrically connected to the sensor and to the switch for activating the switch in response to detection of predetermined light levels by the light sensor;

wherein the control circuit is further comprised of;

high-level adjusting means for manually selecting a level of ambient light as detected by the sensor for activating the switch so as to open the circuit to the light fixture;

low-level adjusting means for manually selecting a level of ambient light as detected by the sensor for activating the switch so as to close the circuit to the light fixture;

said light sensor switch, control circuit, and power source for disposition to a conventional lighting system such that no additional high-voltage conduit is required.

2. A system according to claim 1 wherein:

the control circuit is electrically connected to a multiplicity of switches whereby several lighting circuits may be controlled.

3. A system according to claim 1 wherein:

the power source and the switch are located immediately adjacent to a light fixture.

4. A system according to claim 1 wherein:

the power source and the switch are located immediately adjacent to a light fixture junction box.

5. A system according to claim 1 wherein:

the control circuit further comprises a time-delay buffer for preventing transient changes in ambient light level as the detected by the sensor from effecting the output of the control circuit.

6. A system according to claim 1 wherein:

the light sensor is responsive to ambient light over a range of 5 to 600 foot-candles.

7. A system according to claim 1 wherein:

the switch closes the circuit to the light fixture in the absence of a signal from the control circuit.

8. A light-sensing, light fixture control system comprised of:

a light sensor mounted in optical communication with the ambient light near a light fixture;

a switch interposed in a circuit furnishing electrical power to the light fixture;

a power source for supplying voltage of no greater than 20 volts at an amperage of no greater than 8 amperes to a control circuit; and

a control circuit electrically connected to the sensor and to the switch for activating the switch in response to detection of predetermined light levels by the light sensor;

wherein the control circuit is further comprised of;

high-level adjusting means for manually selecting a level of ambient light as detected by the sensor for activating the switch so as to open the circuit to the light fixture;

the high-level adjusting means comprising;

an enunciator to indicate that the light level detected by the light sensor exceeds the level selected by the high-level adjusting means;

low-level adjusting means for manually selecting a level of ambient light as detected by the sensor for activating the switch so as to close the circuit to the light fixture;

wherein the low-level adjusting means if further comprised of;

an enunciator to indicate when the ambient light level as detected by the sensor is greater than the level selected by the low-level adjusting means; and

a time-delay buffer for preventing transient changes in ambient light level as the detected by the sensor from effecting the output of the control circuit.

9. A system according to claim 8 wherein:

the light sensor is responsive to ambient light over a range of 5 to 600 foot-candles.

10. A system according to claim 9 wherein:

the switch closes the circuit to the light fixture in the absence of a signal from the control circuit.