Battery power supply circuit which supplies correct power polarity irrespective of battery orientation

• US 5,623,550 A
• Filed: 03/08/1995
• Issued: 04/22/1997
• Est. Priority Date: 03/08/1995
• Status: Expired due to Term

• Current Assignee: Etymotic Research Incorporated
• Original Assignee: Etymotic Research Incorporated
• Inventors: Killion, Mead
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): NGUYEN, DUC MINH
• Application Number:
  US08/400,876
• Time in Patent Office: 776 Days
• Field of Search: 363/63, 307/127, 381/69.2, 381/68
• US Class Current: 381/322
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/642 Capacitive arrangements H01L23/49589, H01L23/645, H01L23/647, H01L23/66 take precedence; capacitive effects between wiring layers on the semiconductor body H01L23/5222
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/19041 being a capacitor
• CPC Class Codes: H01L 2924/207 Diameter ranges
• CPC Class Codes: H02H 11/003 using a field effect transistor as protecting element in one of the supply lines
• CPC Class Codes: H02J 7/0034 using reverse polarity correcting or protecting circuits mechanical means of polarity protection H02J7/0045
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H02M 7/219 in a bridge configuration
• CPC Class Codes: H04R 2225/33 Aspects relating to adaptation of the battery voltage, e.g. its regulation, increase or decrease
• CPC Class Codes: H04R 25/602 of batteries

Abstract

A power supply circuit is set forth which overcomes the problems associated with incorrect battery insertion. The power supply circuit includes first and second battery terminals for electrical connection to the battery. The first and second battery terminals are connected to a first transistor switching circuit. The first transistor switching circuit is responsive to power from the battery to through-connect a negative polarity power signal therethrough irrespective of the polarity orientation of the battery. The first and second battery terminals are also connected to a second transistor switching circuit. The second switching circuit is responsive to power from the battery to through-connect a positive polarity power signal therethrough irrespective of polarity orientation of the battery. The negative and positive polarity power signals are available for connection to a load device, such as a hearing aid amplifier. The device is thereby provided with proper power polarity irrespective of the way in which the battery is inserted between the first and second battery terminals.

Claims

1. A hearing aid comprising:

a microphone for transducing audio waves into electronic signals;

an amplifier for amplifying the electronic signals;

a receiver for transducing the amplified electronic signals to sound waves;

a battery for supplying power to the amplifier; and

battery switch means including first and second battery terminals in electrical contact with the battery for supplying power of correct polarity to the amplifier irrespective of battery polarity orientation, the battery switch means comprising

a first transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a negative polarity power signal therethrough, the first transistor switching circuit comprising

a first n-channel MOSFET having gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal the gate terminal being connected to the second battery terminal,

a second n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first batten/terminal, the source terminal of the first n-channel MOSFET being connected to the source terminal of the second n-channel MOSFET and supplying the negative polarity power signal, and

a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second n-channel MOSFETs, the voltage divider circuit comprising

a first resistor having a first terminal connected to the first battery terminal, and a second terminal, and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second n-channel MOSFETs, and

a second transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a positive polarity power signal therethrough.

2. A hearing aid as claimed in claim 1 wherein the second transistor switching circuit comprises:

a) a first p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal; and

b) a second p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first p-channel MOSFET being connected to the source terminal of the second p-channel MOSFET and supplying the positive polarity power signal.

3. A hearing aid as claimed in claim 2 and further comprising a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second p-channel MOSFETs.

4. A hearing aid as claimed in claim 3 wherein the voltage divider circuit comprises:

a) a first resistor having a first terminal connected to the first battery terminal, and a second terminal; and

b) a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second p-channel MOSFETs.

5. A power supply circuit for supplying power from a battery, the power supply circuit comprising:

first and second battery terminals for electrical connection to the battery;

a first transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a negative polarity power signal therethrough irrespective of polarity orientation of the battery, the first transistor switching circuit comprising

a first n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal,

a second n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first n-channel MOSFET being connected to the source terminal of the second n-channel MOSFET and supplying the negative polarity power signal, and

a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second n-channel MOSFETs, the voltage divider circuit comprising

a first resistor having a first terminal connected to the first battery terminal, and a second terminal, and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second n-channel MOSFETs, and

a second transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a positive polarity power signal therethrough irrespective of polarity orientation of the battery.

6. A power supply circuit as claimed in claim 5 wherein the second transistor switching circuit comprises:

a) a first p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal; and

b) a second p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate being connected to the first battery terminal, the source terminal of the first p-channel MOSFET being connected to the source terminal of the second p-channel MOSFET and supplying the positive polarity power signal.

7. A power supply circuit aid as claimed in claim 6 and further comprising a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second p-channel MOSFETs.

8. A power supply circuit as claimed in claim 7 wherein the voltage divider circuit comprises:

a) a first resistor having a first terminal connected to the first battery terminal, and a second terminal; and

b) a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second p-channel MOSFETs.

9. A hearing aid comprising:

a microphone for transducing audio waves into electronic signals;

an amplifier for amplifying the electronic signals;

a receiver for transducing the amplified electronic signals to sound waves;

a battery for supplying power to the amplifier; and

battery switch means including first and second battery terminals in electrical contact with the battery for supplying power of correct polarity to the amplifier irrespective of battery polarity orientation, the battery switch means comprising

a first transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a negative polarity power signal therethrough, and

a second transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a positive polarity power signal therethrough, the second transistor switching circuit comprising

a first p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal;

a second p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first p-channel MOSFET being connected to the source terminal of the second p-channel MOSFET and supplying the positive polarity power signal, and

a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second p-channel MOSFETs, the voltage divider circuit comprising

a first resistor having a first terminal connected to the first battery terminal, and a second terminal, and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second p-channel MOSFETs.

10. A hearing aid as claimed in claim 9 wherein the first transistor switching circuit comprises:

a first n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal; and

a second n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first n-channel MOSFET being connected to the source terminal of the second n-channel MOSFET and supplying the negative polarity power signal.

11. A hearing aid as claimed in claim 10 and further comprising a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second n-channel MOSFETs.

12. A hearing aid as claimed in claim 11 wherein the voltage divider circuit comprises:

a first resistor having a first terminal connected to the first battery terminal, and a second terminal; and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second n-channel MOSFETs.

13. A power supply circuit for supplying power from a battery, the power supply circuit comprising:

first and second battery terminals for electrical connection to the battery;

a first transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a negative polarity power signal therethrough irrespective of polarity orientation of the battery; and

a second transistor switching circuit connected between the first and second battery terminals and responsive to voltage from the battery to through-connect a positive polarity power signal therethrough irrespective of polarity orientation of the battery, the second transistor circuit comprising

a first p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal,

a second p-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first n-channel MOSFET being connected to the source terminal of the second n-channel MOSFET and supplying the negative polarity power signal, and

a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second p-channel MOSFETs, the voltage divider circuit comprising

a first resistor having a first terminal connected to the first battery terminal, and a second terminal, and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second p-channel MOSFETs.

14. A power supply circuit as claimed in claim 13 wherein the first transistor switching circuit comprises:

a first n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the first battery terminal, the gate terminal being connected to the second battery terminal; and

a second n-channel MOSFET having a gate terminal, a drain terminal, and a source terminal, the drain terminal being connected to the second battery terminal, the gate terminal being connected to the first battery terminal, the source terminal of the first n-channel MOSFET being connected to the source terminal of the second n-channel MOSFET and supplying the negative polarity power signal.

15. A power supply circuit as claimed in claim 14 and further comprising a voltage divider circuit disposed between the first and second battery terminals and connected to the source terminals of the first and second n-channel MOSFETs.

16. A power supply circuit as claimed in claim 15 wherein the voltage divider circuit comprises:

a first resistor having a first terminal connected to the first battery terminal, and a second terminal; and

a second resistor having a first terminal connected to the second battery terminal, and a second terminal connected to the second terminal of the first resistor, the second terminals of the first and second resistors being connected to the source terminals of the first and second n-channel MOSFETs.