Systems And Methods For Windshield Deicing

• US 20080223842A1
• Filed: 10/31/2007
• Published: 09/18/2008
• Est. Priority Date: 02/11/2002
• Status: Abandoned Application

• Current Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Original Assignee: The Trustees of Dartmounth College (Dartmouth College)
• Inventors: Sullivan, Charles R., Petrenko, Victor, Nickolayev, Oleg, Kozlyuk, Valeri
• Application Number:
  US11/933,160
• Publication Number:
  US 20080223842A1
• Time in Patent Office: Days
• US Class Current: 219/203
• CPC Class Codes: H05B 1/0236 for vehicles
• CPC Class Codes: H05B 2203/035 Electrical circuits used in resistive heating apparatus
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

Cost efficient, lightweight and rapid windshield deicing systems and methods are disclosed. The systems utilize step-up converters or inverters, or dual-voltage batteries, to provide a voltage high enough to deice a windshield in less than thirty seconds.

Claims

1. A windshield deicing system, comprising:

a low voltage power source for providing low voltage power;

a step-up converter selected from the group consisting of a DC-DC converter and a DC-AC inverter for transforming the low voltage power into high voltage power;

apparatus for enabling the step-up converter; and

a windshield heater, the windshield heater being resistively heated when the converter is enabled and the high voltage power is conducted through the windshield heater.

2. The system of claim 1, wherein the low voltage power source comprises a vehicle battery.

3. The system of claim 1, wherein the windshield heater is disposed on an outer surface of the windshield, and wherein a dielectric layer is disposed over the windshield heater.

4. The system of claim 3, further comprising apparatus for sensing ground fault currents and for interrupting current from the step-up converter when ground fault currents are detected.

5. The system of claim 3, wherein the high voltage power from the step-up converter is isolated from vehicle ground, and further comprising:

apparatus for monitoring integrity of isolation of the high voltage power from ground, and

apparatus for interrupting the high voltage power when a failure of the isolation is detected.

6. The system of claim 1, wherein at least one windshield heater is disposed between a shatter resistant plastic layer and a glass layer.

7. The system of claim 1, wherein the windshield forms part of a vehicle selected from the group consisting of a car, a truck, a rail vehicle, a snowmobile, an airplane, a helicopter or a ship.

8. The system of claim 1, wherein the step-up converter provides the windshield heater with a heating power having a power density in a range from

$500$



W m 2

to

$100<br><br><br><br>\frac{\mathrm{kW}}{m^2},$

where W is power in watts, and m² is an area of the heater in square meters.

9. The system of claim 1, wherein an output voltage of the step-up converter is in a range from 40 V DC to 1000V.

10. The system of claim 1, wherein the windshield heater is selected from an optically transparent metal film, an optically transparent metal oxide, a composite of metal oxides and an optically transparent and electrically conductive polymer material.

11. The system of claim 1, wherein the windshield heater comprises a plurality of sections, each section of which can be powered independently from neighboring sections.

12. The system of claim 1 wherein the step-up converter has a full-power mode wherein it operates continually until the windshield is defrosted, and a reduced power mode selected from the group consisting of intermittent operation and operation at a reduced output voltage of the step-up converter.

13. A windshield deicing system, comprising:

a dual-voltage battery for providing low voltage DC power in a low voltage mode and high voltage DC power in a high voltage mode; and

a switch disposed between the dual-voltage battery and a windshield heater, the switch being closed when the dual-voltage battery is in the high voltage mode and the windshield heater is active,

and wherein the windshield forms part of a vehicle selected from a car, a truck, a rail vehicle, a snowmobile, an airplane, a helicopter or a ship.

14. The system of claim 13, wherein the dual-voltage battery comprises a plurality of batteries, the batteries being connected in parallel in the low voltage mode, and wherein the batteries are connected in series in the high voltage mode.

15. The system of claim 13, wherein the dual-voltage battery provides a voltage in a range of 40V to 360V in the high voltage mode;

and wherein the dual-voltage battery provides the windshield with a heating power having a power density in a range from

$500<br><br><br><br>\frac{W}{m^2}$

to

$100<br><br><br><br>\frac{\mathrm{kW}}{m^2}.$

16. The system of claim 13, wherein the windshield heater is disposed on an outer surface of a glass layer of the windshield, and wherein a dielectric layer is disposed over the windshield heater.

17. The system of claim 16, further comprising apparatus for sensing ground fault currents and for disabling or disconnecting the high-voltage DC power from the windshield heater when ground fault currents are detected.

18. The system of claim 16, wherein the high voltage DC power is isolated from vehicle ground when it is in high-voltage mode.

19. The system of claim 16, further comprising apparatus for monitoring the integrity of isolation of the high voltage DC power from ground and for disconnecting the high-voltage DC power from the windshield heater when a failure of isolation is detected.

20. The system of claim 13, wherein at least one windshield heater is disposed between a shatter resistant plastic layer and a glass layer.

21. The system of claim 13, wherein the windshield heater is selected from an optically transparent metal film, an optically transparent metal oxide, a composite of metal oxides and an optically transparent and electrically conductive polymer material.

22. The system of claim 13, wherein the windshield heater comprises a plurality of sections, each section electrically isolated from neighboring sections, and wherein the high voltage DC power is separately applied to each section.

23. A method of deicing a windshield, comprising:

providing a source of low voltage power;

transforming the low voltage power into high voltage power; and

providing the high voltage power to a windshield heater to resistively heat the windshield heater and deice a surface of the windshield.

24. The method of claim 23, wherein the step of transforming the low voltage power into high voltage power comprises switching a dual-voltage battery from a parallel configuration into a series configuration.

25. The method of claim 23, wherein the step of transforming the low voltage power into high voltage power comprises utilizing a step-up converter selected from the group consisting of a DC-DC converter and a DC-AC inverter.