Very close differential outdoor lighting control

• US 3,351,762 A
• Filed: 07/06/1964
• Issued: 11/07/1967
• Est. Priority Date: 07/06/1964
• Status: Expired due to Term

• Current Assignee: Harold T. Adkins, Robert H. Pierce
• Original Assignee: Harold T. Adkins, Robert H. Pierce
• Inventors: Adkins, Harold T., Pierce, Robert H.
• Application Number:
  US04/380,363
• Time in Patent Office: 1,219 Days
• US Class Current: 250/206
• 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

Claims

2. AN AMBIENT LIGHT-RESPONSIVE CONTROL CIRCUIT COMPRISING, IN COMBINATION, A PHOTO SENSITIVE CELL;

SWITCH MEANS IN OPERATIVE CIRCUIT CONNECTION WITH SAID PHOTO SENSITIVE CELL;

SAID CELL EFFECTING CLOSURE OF SAID SWITCH MEANS RESPONSIVE TO ONE LEVEL OF AMBIENT LIGHT INCIDENT UPON SAID CELL AND OPENING OF SAID SWITCH MEANS RESPONSIVE TO ANOTHER LEVEL OF AMBIENT LIGHT INCIDENT UPON SAID CELL;

AND MEANS OPERABLE TO REDUCE THE DIFFERENTIAL BETWEEN THE RESPECTIVE AMBIENT LIGHT LEVELS EFFECTING CLOSING AND OPENING OF SAID SWITCH MEANS, SAID DIFFERENTIAL REDUCING MEANS COMPRISING MEANS OPERATIVELY ASSOCIATED WITH SAID CELL AND CONTROLLING THE SENSITIVITY OF RESPONSE OF THE LATTER BY MODULATING ENERGY SUPPLIED TO SAID CELL;

SAID MEANS HAVING AN ENERGY MODULATING EFFECT WHICH VARIES AS A FUNCTION OF THE DURATION OF AN IMMEDIATELY PRECEDING AMBIENT LIGHT LEVEL OF SUBSTANTIAL DURATION;

SAID MEANS DECREASING THE SENSITIVITY OF RESPONSE OF SAID CELL WITH RESPECT TO A CHANGE FROM ONE LEVEL OF AMBIENT LIGHT EFFECTING OPERATION OF SAID SWITCH MEANS WHILE INCREASING THE SENSITIVITY OF RESPONSE OF SAID CELL WITH RESPECT TO THE OTHER LEVEL OF AMBIENT LIGHT EFFECTING OPERATION OF SAID SWITCH MEANS.