Headlight, windshield wiper control system

• US 4,956,562 A
• Filed: 09/15/1989
• Issued: 09/11/1990
• Est. Priority Date: 03/27/1989
• Status: Expired due to Term

• Current Assignee: Charles E. Benedict
• Original Assignee: Benedict Engineering Company, Inc.
• Inventors: Benedict, Charles E., Stumpf, Donald M.
• Primary Examiner(s): Shoop, Jr., William M.
• Assistant Examiner(s): Ip, Paul
• Application Number:
  US07/409,612
• Time in Patent Office: 361 Days
• Field of Search: 307/9.1-10.8, 315/82, 315/83, 340/641, 318/444-447
• US Class Current: 307/10.8
• CPC Class Codes: B60Q 1/143 combined with another condition, e.g. using vehicle recognition from camera images or activation of wipers
• CPC Class Codes: B60Q 2300/312 Adverse weather
• CPC Class Codes: B60Q 2300/314 Ambient light

Abstract

A control system for turning on the headlights (and parking lights) of an automobile when the windshield wipers are turned on, has a gating circuit that operates relay circuits to the headlights, the gating circuit electronically latching "in" the headlight relay circuit so that the headlights remain on when the windshield wiper is turned off in order to avoid inadvertent turning off of the hedlights at night time and the gate circuit electronically turning off the headlight (and parking light) relay circuits whenever the headlight switch is turned on or whenever the ignition is turned off, thus assuring that the headlights will remain on until the headlights and ignition switches are turned off. The relay circuits controlled by the gating circuit may operate a mechanically or electrically latched relay device to hold the headlights (and parking lights) on until the relay circuit controlled by the gating circuit operates the mechanically or electrically latched relay device to turn the headlights off. Ambient light and moisture sensors may be used to effect the turning on of the windshield wiper switch.

Claims

1. An automatic system for controlling the turning on of vehicle headlights when ignition and windshield wipers are turned on and for keeping them on when the wipers are turned off, comprising on-off switches for the ignition, wipers and headlights, a first relay circuit, a relay switch, said relay switch having means for connecting said headlights to power supply means, said first relay circuit being alternately connectable to actuating means for said relay switch which governs the connection of said headlights to said power supply means, said power supply means connected to said first relay circuit, control means for said first relay circuit, logic circuit means connecting the outputs of said ignition and headlight switches to the control means for said first relay circuit, said logic circuit means connecting the outputs of said ignition, wipers and headlights to form a latching circuit, said latching circuit producing a signal output to activate said control means for said first relay circuit to turn the headlights on when the ignition and wiper switches are turned on, said latching circuit continuing to produce such signal output when the wiper switch is turned off.

2. The invention of claim 1, and a second relay circuit, said first and second relay circuits being alternately connectable to said operating means for said relay switch, control means for said second relay circuit, said logic circuit means connecting the outputs of said ignition, wipers and headlights to the control means for said second relay circuit which is operative to turn the headlights off in response to the turning on of the on-off switch for the headlights, or the turning off of the ignition switch.

3. The invention of claim 2, said first relay circuit operating a mechanical latching means operative to hold the headlights turned on until the second relay circuit is activated.

4. The invention of claim 3, said second relay circuit operating said mechanical latching means to hold the headlights turned off until the first relay circuit is activated or until the headlight switch is turned on.

5. The invention of claim 1, in which a plurality of first logic circuit means are connected in parallel, each first logic circuit means producing a first signal output to said first relay circuit.

6. The invention of claim 2, in which a plurality of second logic circuit means are connected in parallel, each second logic circuit means producing a second signal output to said second relay circuit.

7. The invention of claim 2, in which a plurality of first logic circuit means are connected in parallel, each first logic circuit means producing a first signal output, and in which a plurality of second logic circuit means are connected in parallel, each second logic circuit means producing a second signal output.

8. The invention of claim 5, in which a plurality of first signal outputs are operative in series to activate said first relay circuit.

9. The invention of claim 6, in which a plurality of second signal outputs are operative in series to activate said second relay circuit.

10. The invention of claim 5, in which a plurality of first signal outputs are operative in parallel to activate said first relay circuit.

11. The invention of claim 1 in which said logic circuit means comprises the output of said ignition having three branches connected respectively, to a first AND gate means, a first inverter, and a second AND gate means, the output of said headlights having two branches connected respectively to said first AND gate means and a second inverter, the output of said wipers being connected to said second AND gate means, the output of said first AND gate means being connected to OR gate means, the output of said first inverter connected to said OR gate means, the output of said second inverter connected to said second AND gate means, the output of said OR gate means connected to a first NOR gate means, the output of said second AND gate means connected to a second NOR gate means, the output of each respective NOR gate means connected to the input of the other NOR gate means, the output of the first NOR gate means connected to a control means for said first relay circuit, and a second relay circuit operative to turn the headlights off when the switch for the headlights is turned on or when the ignition is turned off, the output of said second NOR gate means connected to a control means for said second relay circuit.

12. The invention of claim 1 in which said logic circuit means comprises the output of said ignition having three branches connected respectively to a first AND gate means, a first inverter, and a second AND gate means, the output of said headlights having two branches connected respectively to said first AND gate means and a second inverter, the output of said wipers being connected to said second AND gate means, the output of said first AND gate means being connected to OR gate means, the output of said first inverter connected to said OR gate means, the output of said second inverter connected to a third AND gate means, the output of said OR gate means connected to a first NOR gate means, the output of said second AND gate means connected to said third AND gate means, the output of which is connected to a second NOR gate means, the output of said first NOR gate means connected to the input of said second NOR gate means and to the control means for said first relay circuit, and a second relay circuit operative to turn the headlights off when the switch for the headlights is turned on, or when the ignition switch is turned off, the output of said second NOR gate means connected to the input of said first NOR gate means and to the control means for said second relay circuit.

13. The invention of claim 1, and light activated transistor means between the on-off switches and the relay circuits which isolate the input voltages from the transistor outputs.

14. The invention of claim 1, each relay circuit having an input connected to an on-off switch, and RC circuit means in each input to protect the relay circuit from excessive voltages.

15. The invention of claim 14, and thermistor means connecting the inputs to ground.

16. The invention of claim 1, in which said operating means for said relay switch includes a low voltage power supply, and means for filtering transients and high voltage surges from such power supply and passing them to ground.

17. The invention of claim 1, means for sensing the ambient light level, and means for effectively turning on the windshield wiper switch when the ambient light level is below a predetermined level.

18. The invention of claim 17, in which the means for effectively turning on the windshield wiper switch is connected to a bypass around said switch.

19. The invention of claim 1, means for sensing the moisture level, and means for effectively turning on the windshield wiper switch when the moisture level is above a predetermined level.

20. The invention of claim 19, in which the means for effectively turning on the windshield wiper switch is connected to a bypass around said switch.

21. The invention of claim 17 in which the means for sensing the ambient light level is connected to the base of a transistor which conducts and lowers the voltage at the base when the ambient light is below a predetermined level.

22. The invention of claim 21 in which the light sensing means and the transistor are in series with each other and are in parallel with a line between a low voltage power supply and the bypass.

23. The invention of claim 1, means for sensing the ambient light level, means for sensing the moisture level, said means connected in parallel, and means connected to said light sensing and moisture sensing means for effectively turning on the windshield wiper when the ambient light level is below a predetermined level or when the moisture level is above a predetermined level.