Photoelectric control circuit

• US 3,345,536 A
• Filed: 02/21/1964
• Issued: 10/03/1967
• Est. Priority Date: 02/21/1964
• Status: Expired due to Term

• Current Assignee: Edison International
• Original Assignee: Carl E. Atkins, Robert L. Ziolkowski
• Inventors: Atkins, Carl E., Ziolkowski, Robert L.
• Application Number:
  US04/346,490
• Time in Patent Office: 1,320 Days
• US Class Current: 315/83
• CPC Class Codes: B60Q 1/1423 Automatic dimming circuits, i.e. switching between high beam and low beam due to change of ambient light or light level in road traffic
• CPC Class Codes: B60Q 2300/42 oncoming vehicle

Claims

1. A HEADLIGHT CONTROL CIRCUIT FOR AN AUTOMOBILE WHICH AUTOMATICALLY DIMS THE HEADLAMPS OF THE AUTOMOBILE AT THE APPROACH OF AN ONCOMING LIGHTED VEHICLE COMPRISING;

AN ELECTROMAGNETIC RELAY HAVING ARMATURE MEANS CONNECTED TO A SOURCE OF DIRECT CURRENT POTENTIAL, A FIRST CONTACT MEANS CONNECTED TO THE LOW BEAM FILAMENTS OF THE HEADLAMPS, A SECOND CONTACT MEANS CONNECTED TO THE HIGH BEAM FILAMENTS OF THE HEADLAMPS AND A COIL WHICH CAN BE ENERGIZED AND DE-ENERGIZED TO POSITION THE ARMATURE MEANS IN CONTACT WITH THE FIRST OR SECOND CONTACT MEANS;

AMPLIFYING MEANS HAVING AN OUTPUT CIRCUIT COUPLED TO SAID COIL TO SUPPLY CURRENT THERETO AND AN INPUT CIRCUIT WHICH INCLUDES A FIELD EFFECT TRANSISTOR HAVING A GATE, A SOURCE, AND A DRAIN ELECTRODE;

A PHOTOELECTRIC CELL POSITIONED FOR RECEIVING LIGHT FROM THE HEADLAMPS OF APPROACHING VEHICLES, SAID PHOTOELECTRIC CELLS HAVING A CATHODE CONNECTED TO THE GATE ELECTRODE TO SAID FIELD EFFECT TRANSISTOR SO THAT LIGHT VARIATIONS APPLIED TO SAID PHOTOELECTRIC CELL PRODUCE VARIATIONS FROM A BIAS LEVEL OF OUTPUT CURRENT OF SAID AMPLIFYING MEANS, AND A CONTROLLED SOURCE OF LIGHT WHICH IS POSITIONED SO THAT LIGHT THEREFROM IS DIRECTED AT SAID PHOTOELECTRIC CELL TO PRODUCE SAID BIAS LEVEL OF OUTPUT CURRENT OF SAID AMPLIFYING MEANS WHICH PERMITS ENERGIZATION OF THE HIGH BEAM FILAMENTS, SAID VARIATIONS FROM SAID LEVEL OF OUTPUT CURRENT CAUSING THE HIGH BEAM FILAMENTS TO BE DE-ENERGIZED AND THE LOW BEAM FILAMENTS TO BE ENERGIZED.