ELECTRONIC LIGHTING CONTROL RESPONSIVE TO AMBIENT LIGHT

• US 3,735,141 A
• Filed: 09/01/1971
• Issued: 05/22/1973
• Est. Priority Date: 09/01/1971
• Status: Expired due to Term

• Current Assignee: Thomas E. Beling
• Original Assignee: Thomas E. Beling
• Inventors: Beling, Thomas E.
• Primary Examiner(s): Stolwein, Walter
• Application Number:
  US05/176,808
• Time in Patent Office: 629 Days
• Field of Search: 250/206,214R,209,208,205 315/151,158,159,156 307/117,311
• US Class Current: 250/214.00R
• CPC Class Codes: H05B 47/11 by determining the brightness or colour temperature of ambient light
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

In the disclosed control, a light source is turned on and off bistably in response to ambient light. To do this, a photoresistor or photocell, whose resistance increases with decreasing light, is exposed to the ambient light. The photoresistor or cell forms part of a voltage-energized voltage divider, and is connected across a neon lamp from which the cell is shielded. When the ambient light is sufficiently dim the lamp is lit. The current through the neon lamp is intensified with a second photoresistor or photocell in series with the lamp and subject to decreasing resistance as the lamp brightens. This constitutes a positive feedback and holds the neon lamp on. A third photoresistor or photocell in series with a switch responds to the bright lamp to turn on the switch and hence the light source. When the ambient light reduces beyond a given threshold the first photocell turns off the lamp and the second photocell increases its resistance enough to hold off the lamp.

Claims

1. A lighting control for turning an illuminating source on and off in response to ambient light conditions, comprising first photoelectric means responsive to the ambient light, regenerative means coupled to said first photoelectric means for assuming one condition when the ambient light on said first photoelectric means exceeds a given value and for assuming a second condition when the ambient light on said first photoelectric means is less than a given value, said regenerative means including light means coupled to said first photoelectric means for turning brighter or dimmer in response to the first photoelectric means, said regenerative means further including second photoelectric means responsive to light from said light means and electrically coupled to said light means for making said light means brighter as said light means turns bright and dimmer as said light means turns dim, and control means coupled to said regenerative means and responsive to the condition of said regenerative means for turning the source on or off.

2. A control as in claim 1, wherein said light means becomes brighter as said first photoelectric means is subject to less ambient light.

3. A control as in claim 1, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

4. A control as in claim 2, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

5. A control as in claim 1, wherein said first photoelectric means includes a voltage divider adapted to be connected across a voltage source and having a variable resistance photocell connected across said light means so as to increase the voltage across said light means when the ambient light increases.

6. A control as in claim 3, wherein said first photoelectric means includes a voltage divider adapted to be connected across a voltage source and having a variable resistance photocell connected across said light means so as to increase the voltage across said light means when the ambient light increases.

7. A control as in claim 1, wherein said light means includes a voltage breakdown device.

8. A control as in claim 7, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

9. A control as in claim 7, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

10. A control as in claim 7, wherein said first photoelectric means includes a voltage divider adapted to be connected across a voltage source and having a variable resistance photocell connected across said light means so as to increase the voltage across said light means when the ambient light increases.

11. A control as in claim 1, wherein said control means includes third photoelectric means optically coupled and responsive to said light means and signal responsive means connected in series with said third photoelectric means, said third photoelectric means decreasing its resistance in response to light from said light means so as to increase the signal to said signal responsive means as said light becomes brighter.

12. A control as in claim 11, wherein said signal responsive means includes a relay coil forming a part of a relay.

13. A control as in claim 11, wherein said current responsive means includes a semiconductor switch.

14. A control as in claim 7, wherein said breakdown device includes a neon lamp.

15. A control as in claim 11, wherein said light means becomes brighter as said first photoelectric means is subject to less ambient light.

16. A control as in claim 11, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

17. A control as in claim 15, wherein said second photoelectric means includes a photoelectric resistor in series with said light means and responsive to lower its resistance when subjected to more light from said light means.

18. A control as in claim 11, wherein said first photoelectric means includes a voltage divider adapted to be connected across a voltage source and having a variable resistance photocell connected across said light means so as to increase the voltage across said light means when the ambient light increases.

19. A lighting control for turning an illumination source on and off in response to ambient light conditions, comprising photoelectric means responsive to the ambient light, said photoelectric means assuming variable electrical conditions in response to variatiOn of the ambient light conditions, light component means coupled to said photoelectric means for producing varying conditions of brightness in response to changes in the electrical condition of said photoelectric means, photoelectric component means close enough to the light component means to be responsive to light therefrom and exhibiting electrical conditions which vary in response to light incident thereon and regeneratively coupled to said light component means for making the light from said light component means even brighter as the light turns bright and dimmer as the light turns dim so that at any time said component means exhibit one state or another corresponding to extreme conditions, and control means coupled to one of said component means and responsive to one or the other states for turning the source on or off.