CURRENT-PROTECTED DRIVER CIRCUIT FOR IGNITION EXCITER UNIT

• US 20090107149A1
• Filed: 06/03/2008
• Published: 04/30/2009
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Trumbo, Dale A., Lei, Steven A., Galey, Larry L.
• Granted Patent: US 8,027,142 B2
• Time in Patent Office: Days
• US Class Current: 60/772
• CPC Class Codes: F02C 7/266 Electric sparking plugs H01T
• CPC Class Codes: F02P 3/055 with protective means to prevent damage to the circuit, e.g. semiconductor devices or the ignition coil
• CPC Class Codes: F05D 2220/50 for auxiliary power units (APU's)

Abstract

Methods and apparatus are provided for driving an ignition exciter unit. An apparatus is provided for a driver circuit for use with an ignition exciter unit, the driver circuit having an input terminal and an output terminal. A first current-protected circuit is coupled to the input terminal and the output terminal, wherein the first current-protected circuit is current-limited. A second current-protected circuit coupled to the input terminal and the output terminal. The driver circuit further comprises a controller coupled to the first current-protected circuit and the second current-protected circuit. The controller is configured to activate the first current-protected circuit for a first time interval and activate the second current-protected circuit after the first time interval and prior to when the ignition exciter unit begins operating.

Claims

1. A method for driving an ignition exciter unit, the ignition exciter unit having an input coupled to a first current-protected circuit and a second current-protected circuit, the method comprising:

supplying a first current to the ignition exciter unit from the first current-protected circuit for a first time interval, wherein the first current is limited by the first current-protected circuit; and

supplying a second current to the ignition exciter unit from the second current-protected circuit after the first time interval and prior to when the ignition exciter unit begins operating.

2. The method of claim 1, further comprising pre-charging an input capacitance of the ignition exciter unit.

3. The method of claim 1, further comprising activating the first current-protected circuit for the first time interval.

4. The method of claim 3, further comprising activating the second current-protected circuit after the first time interval and prior to when the ignition exciter unit begins operating.

5. The method of claim 4, further comprising deactivating the first current-protected circuit in response to activating the second current-protected circuit.

6. The method of claim 5, further comprising deactivating the second current-protected circuit when the ignition exciter unit completes an ignition cycle.

7. The method of claim 4, further comprising deactivating the first current-protected circuit and the second current-protected circuit when the ignition exciter unit completes an ignition cycle

8. The method of claim 3, wherein the first current-protected circuit comprises a current-protected switch coupled to a resistor.

9. The method of claim 8, wherein the current-protected switch is an automotive high-side switch.

10. The method of claim 1, wherein the first time interval is 20 milliseconds.

11. A driver circuit for use with an ignition exciter unit, the driver circuit having an input terminal and an output terminal, the driver circuit comprising:

a first current-protected circuit coupled to the input terminal and the output terminal, the first current-protected circuit being current-limited;

a second current-protected circuit coupled to the input terminal and the output terminal; and

a controller coupled to the first current-protected circuit and the second current-protected circuit, the controller being configured to;

activate the first current-protected circuit for a first time interval; and

activate the second current-protected circuit after the first time interval and prior to when the ignition exciter unit begins operating.

12. The driver circuit of claim 11, wherein the first current-protected circuit further comprises:

a current-protected switch coupled to the input terminal; and

a resistor coupled to the current-protected switch and the output terminal.

13. The driver circuit of claim 12, wherein the current-protected switch is an automotive high-side switch.

14. The driver circuit of claim 11, wherein the second current-protected circuit comprises a current-protected switch.

15. The driver circuit of claim 14, wherein the current-protected switch is an automotive high-side switch.

16. The driver circuit of claim 11, wherein the controller is configured to:

deactivate the first current-protected circuit in response to activating the second current-protected circuit; and

deactivate the second current-protected circuit when the ignition exciter unit completes an ignition cycle.

17. A driver circuit for use with an ignition exciter unit, the driver circuit being coupled to an energy source and an input of the ignition exciter unit, the driver circuit comprising:

a first current-protected switch coupled to the energy source and an input of the ignition exciter unit;

a second current-protected switch coupled to the energy source and the input of the ignition exciter unit;

means for limiting current through the first current-protected switch;

means for activating the first current-protected switch for a first time interval; and

means for activating the second current-protected switch after the first time interval and prior to when the ignition exciter unit begins operating.

18. The driver circuit of claim 17, wherein the first current-protected switch is an automotive high-side switch.

19. The driver circuit of claim 17, wherein the second current-protected switch is an automotive high-side switch.

20. The driver circuit of claim 17, wherein the means for limiting current through the first current-protected switch comprises a resistor coupled to the first current-protected switch and the input of the ignition exciter unit.