AUTOMOTIVE BALANCED MICROPHONE SYSTEM AND METHOD OF FORMING SAME

• US 20070291962A1
• Filed: 05/25/2007
• Published: 12/20/2007
• Est. Priority Date: 05/26/2006
• Status: Abandoned Application

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Spence, William, Turnbull, Robert, Watson, Alan
• Application Number:
  US11/753,994
• Publication Number:
  US 20070291962A1
• Time in Patent Office: Days
• US Class Current: 381/113
• CPC Class Codes: B60R 1/12 Mirror assemblies combined with other articles, e.g. clocks
• CPC Class Codes: B60R 11/0247 for microphones or earphones
• CPC Class Codes: B60R 2011/0033 Rear-view mirrors
• CPC Class Codes: H04R 2410/00 Microphones
• CPC Class Codes: H04R 2499/13 Acoustic transducers and sound field adaptation in vehicles
• CPC Class Codes: H04R 3/00 Circuits for transducers , loudspeakers or microphones

Abstract

An automotive balanced microphone system (300) includes a microphone (303) located in a vehicle mirror (301) connected in a balanced configuration for eliminating noise. A split resistor network (305) is used for supplying a supply voltage to the balanced microphone (303). The split resistor network (305) allows the microphone (303) to be easily powered while noise induced into the supply lines can easily cancelled at the microphone output for use with an electronic device (309).

Claims

1. An automotive balanced microphone system comprising:

at least one microphone located in a vehicle mirror connected in a balanced configuration for eliminating noise; and

a split resistor network for supplying a supply voltage to the at least one balanced microphone.

2. An automotive balanced microphone system as in claim 1, wherein the split resistor network is comprised of a plurality of resistor sections.

3. An automotive balanced microphone system as in claim 2, wherein the plurality of resistor sections have substantially the same resistance.

4. An automotive balanced microphone system as in claim 1, wherein the split resistor network includes at least one predetermined test point.

5. An automotive balanced microphone system as in claim 1, further comprising at least one bypass capacitor for shunting radio frequency (RF) energy from the split resistor network to ground.

6. A balanced microphone system for use in a vehicle comprising:

at least one microphone connected in an electrically balanced configuration;

a resistor network having a plurality of resistive sections for supplying a voltage to the at least one microphone; and

at least one coupling capacitor for coupling the output of the at least one microphone to an electronic device.

7. A balanced microphone system for use in a vehicle as in claim 6, further comprising:

a predetermined test point common the resistive network for determining the operational status of the mirror system.

8. A balanced microphone system for use in a vehicle as in claim 6, wherein the resistive sections have substantially the same resistance.

9. A balanced microphone system for use in a vehicle as in claim 6, further comprising at least one bypass capacitor positioned across the output of the microphone.

10. A balanced microphone system for use in a vehicle as in claim 6, further comprising at least one bypass capacitor for shunting radio frequency (RF) energy from the plurality of resistive sections to ground.

11. A balanced microphone system for use in a vehicle as in claim 6, further comprising at least one ferrite choke for preventing radio frequency (RF) energy from being provided to the input of the at least one microphone.

12. A method for forming an automotive microphone system comprising the steps of:

configuring at least one microphone with an electrically balanced output;

supplying a voltage to the at least one microphone using a split resistor network; and

configuring the split resistor network such that it has a plurality of legs.

13. A method for forming an automotive microphone system as in claim 12, further comprising the step of:

establishing a value for the plurality of legs such that they are substantially equal.

14. A method for forming an automotive microphone system as in claim 12, further comprising the step of:

blocking radio frequency (RF) energy from entering the at least one microphone input using at least one choke.

15. A method for forming an automotive microphone system as in claim 14, wherein the at least one choke is a ferrite bead.

16. A method for forming an automotive microphone system as in claim 12, further comprising the step of:

forming a predetermined test point at the plurality of legs of the resistive network for testing the operational status of the automotive microphone system.

17. A method for forming an automotive microphone system as in claim 12, further comprising the step of:

connecting at least one bypass capacitor to the split resistor network for shunting radio frequency (RF) energy to ground.