Electrostatic windshield wiper and headlight control circuit

• US 5,666,005 A
• Filed: 11/07/1995
• Issued: 09/09/1997
• Est. Priority Date: 11/07/1995
• Status: Expired due to Fees

• Current Assignee: Stephen Lionel Watford
• Original Assignee: Stephen Lionel Watford
• Inventors: Watford, Stephen Lionel
• Primary Examiner(s): Elms, Richard T.
• Application Number:
  US08/551,767
• Time in Patent Office: 672 Days
• Field of Search: 307/9.1, 307/10.1, 307/10.8, 361/190, 361/170, 315/77, 315/82, 315/83
• 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

Abstract

An electrostatic windshield wiper and headlight control circuit, for coupling an automobile windshield wiper circuit with automobile lamps and remotely actuating the automobile lamps; comprising a metal oxide semiconductor field effect transistor (Q1) and a relay. The metal oxide semiconductor field effect transistor (Q1) has an insulated gate for maintaining physical electrical isolation between the windshield wiper and automobile lamp circuits, and for operating with voltage only; it produces and uses static electricity to actuate the actuator circuit of the relay. The relay is for remotely controlling power to the automobile lamps. Voltage from the windshield wiper circuit is used to produce an electrostatic field, which actuates the actuator circuit of the relay, in effect, the isolated switching element of the relay becomes activated, and automatically transfers power directly from the vehicle'"'"'s battery to connecting lamps. The lamps remain "on" after the wiper circuit is turned "off" to ensure safety.

Claims

1. An electrostatic control circuit for activating an automobile lighting system in response to activation of a windshield wiper system, said control circuit comprising

an insulated-gate field effect transistor having a gate for connection to a windshield wiper circuit, a drain for connection to a power supply and a source for connection to ground, said gate having no physical contact with said drain and said source;

a rectifier having a gate connected to said source of said electron valve and to said ground, a cathode for connection to ground and an anode; and

a relay having a coil connected to and between said anode of said rectifier and the power supply, at least one stationary contact for connection to a lighting circuit and at least one normally open movable contact for connection to the power supply whereby upon activation of the windshield wiper circuit and a flow of current from the power supply through said coil of said relay, said movable contact closes on said stationary contact to effect a flow of current to the lighting circuit from the power supply.

2. A control circuit as set forth in claim 1 wherein said electron valve is an enhancement mode metal-oxide-semiconductor field effect transistor.

3. A control circuit as set forth in claim 2 wherein said rectifier is a thyristor.

4. A control circuit as set forth in claim 1 which further comprises a normally closed reset switch connected to and between said coil of said relay and the power supply for selectively interrupting a flow of current to the lighting circuit.

5. A control circuit as set forth in claim 1 which further comprises a first resistor connected to and between said drain of said electron valve and the power supply and a second resistor connected to and between said supply of said electron valve and ground.

6. A control circuit as set forth in claim 1 which further comprises a fuse connected to and between said gate of said electron valve and the windshield wiper circuit.

7. An electrostatic control circuit for activating an automobile lighting system in response to activation of a windshield wiper system, said control circuit comprising

a first insulated-gate field effect transistor having a gate for connection to a windshield wiper circuit, a drain for connection to a power supply and a source, said gate having no physical contact with said drain and said source;

a second insulated-gate field effect transistor having a gate, a drain for connecting to the power supply, and a source for connection to ground;

a relay having a coil connected to and between said drain of said second transistor and the power supply, at least one stationary contact for connection to a lighting circuit and at least one normally open movable contact for connection to the power supply; and

a sub-circuit network for maintaining a constant threshold voltage at said gate of said second transistor, said network connected to said supply of said first transistor, said gate of said second transistor and ground.

8. A control circuit as set forth in claim 7 wherein said network includes a diode having a cathode and an anode;

first resistor connected to and between said supply of said first transistor and said cathode of said diode;

a capacitor having a negative lead connected to said anode of said diode and a positive lead connected to said gate of said second transistor; and

a second resistor connected at one end to said supply of said first transistor and said positive lead of said capacitor, and at an opposite end to said anode of said diode, said negative lead of said capacitor and ground.

9. A control circuit as set forth in claim 8 wherein each transistor is an enhancement mode metal-oxide-semiconductor field effect transistor.

10. A control circuit as set forth in claim 8 which further comprises a normally closed reset switch connected to and between said coil of said relay and the power supply for selectively interrupting a flow of current to the lighting circuit.

11. A control circuit as set forth in claim 8 which further comprises a third resistor connected to and between said drain of said first transistor and the power supply.

12. A control circuit as set forth in claim 8 which further comprises a fuse connected to and between said gate of said first transistor and the windshield wiper circuit.

13. In combination,

a first electrical circuit;

a second electrical circuit isolated from said first electrical circuit;

a power supply common to each said electrical circuit; and

an electrostatic control circuit for activating said first electrical circuit in response to connection of said second electrical circuit to said power supply, said control circuit including a relay having at least one stationary contact connected to said first electrical circuit, at least one normally open movable contact connected to said power supply and a coil connected to said power supply for moving said movable contact onto said stationary contact in response to a flow of current through said coil;

an insulated gate field effect transistor having a gate connected to said second electrical circuit, a drain connected to said power supply, and a source, said gate having no physical contact with said drain and said source; and

a relay driver connected to and between said source of said transistor and said coil of said relay to energize said coil in response to activating of said second electrical circuit.

14. The combination as set forth in claim 13 wherein said relay driver is a rectifier having a gate connected to said source of said electron valve, an anode connected to said coil and a cathode connected to ground.

15. The combination as set forth in claim 13 wherein said relay driver is a second transistor having a gate connected to said source of the first transistor, a drain connected to said coil and a source connected to ground.

16. The combination as set forth in claim 15 which further comprises a sub-circuit network for maintaining a constant threshold voltage at said gate of said second transistor, said network being connected to said source of said first transistor, said gate of said second transistor and ground.

17. The combination as set forth in claim 16 wherein said network includes a diode having a cathode and an anode;

and first resistor connected to and between said source of said first transistor and said cathode of said diode;

a capacitor having a negative lead connected to said anode of said diode and a positive lead connected to said gate of said second transistor and a second resistor connected at one end to said source of said first transistor and said positive lead of said capacitor, and at an opposite end to said anode of said diode, said negative lead of said capacitor and ground.

18. The combination as set forth in claim 13 wherein said first electrical circuit is a lighting circuit and said second electrical circuit is a windshield wiper circuit in an automobile.

19. The combination as set forth in claim 13 where said transistor is an enhancement mode metal-oxide-semiconductor field effect transistor.

20. A control circuit for activating an automobile lighting system in response to activation of a windshield wiper system, said control circuit comprising

an electron valve having a gate for connection to a windshield wiper circuit, a drain for connection to a power supply and a source for connection to ground;

a rectifier having a gate connected to said source of said electron valve and to said ground, a cathode for connection to ground and an anode;

a relay having a coil connected to and between said anode of said rectifier and the power supply, at least one stationary contact for connection to a lighting circuit and at least one normally open movable contact for connection to the power supply whereby upon activation of the windshield wiper circuit and a flow of current from the power supply through said coil of said relay, said movable contact closes on said stationary contact to effect a flow of current to the lighting circuit from the power supply; and

a normally closed reset switch connected to and between said coil of said relay and the power supply for selectively interrupting a flow of current to the lighting circuit.