Inductive wireless data connection

• US 5,325,046 A
• Filed: 12/18/1991
• Issued: 06/28/1994
• Est. Priority Date: 12/18/1991
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Apple Computer Incorporated (Apple Inc.)
• Inventors: Cheponis, Mike, Young, Steven J.
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): BERHANE, ADOLF D
• Application Number:
  US07/810,714
• Time in Patent Office: 923 Days
• Field of Search: 323/355, 323/356, 323/359, 323/361, 323/345, 323/247, 340/870.3, 340/870.31, 340/870.32, 340/870.34
• US Class Current: 323/356
• CPC Class Codes: G05F 1/32 using magnetic devices having a controllable degree of saturation as final control devices
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: H01F 2038/143 for signals
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10

Abstract

A system that allows inductive connectors to be electrically coupled without having to mechanical align the same. The connectors have a primary coil coupled to a secondary coil. The primary coil transmits either power or digital signals to the secondary coil. The power induced onto the secondary coil is a function of the distance between coils. The farther apart the coils are, the less power is transmitted to the secondary coil. To insure that the proper level of power is received by the secondary coil, a feedback circuit is incorporated to vary the output of power on the primary coil as a function of the voltage induced onto the secondary connectors. If connectors are spaced apart beyond a predetermined distance, the feedback system increases the power on the primary coil.

Claims

1. An inductive electrical system, comprising;

a first primary inductive connector that provides power at a power frequency;

a first secondary inductive connector that receives said power from said first primary inductive connector;

first feedback means for monitoring a level of said power and generating a first feedback signal that is a function of said power level and which is transmitted from said secondary inductive connector to said primary inductive connector; and

,

power varying means for receiving said first feedback signal and varying said power level in response to said first feedback signal.

2. The system as recited in claim 1, wherein said first feedback means and said power vary means includes;

first voltage control oscillator means connected to said first secondary inductive connector for providing said first feedback signal to said first secondary inductive connector, said first feedback signal having a first feedback frequency that is different than said power frequency, said first voltage control oscillator means being adapted to change said firs feedback frequency as a function of said power level, said first feedback signals being transmitted from said first secondary inductive connector to said first primary inductive connector;

first phase lock loop means connected to said first primary inductive connector for receiving said first feedback signals and providing a first power conversion signal that has a first power conversion signal voltage, said first power conversion signal voltage being dependent upon said first feedback frequency of said first feedback signals;

first automatic gain control means coupled to said first phase lock loop means and said first primary inductive connector for receiving said first power conversion signal and controlling said power provided by said first primary inductive connector as a function of said first power conversion signal voltage.

3. The system as recited in claim 2, wherein said first automatic gain control increases said power of said first primary inductive connector when said first conversion signal voltage is above a predetermined value, and decreases said power of said first primary inductive connector when said first conversion signal voltage is below a predetermined value.

4. The system as recited in claim 2, further comprising a first filter coupled to said first primary inductive connector and said first phase lock loop means to filter out said power frequency from being received by said first phase lock loop.

5. The system as recited in claim 4, wherein said power frequency is less than said first feedback frequency and said first filter is a first high pass filter that filters out frequencies below said first feedback frequency.

6. An inductive electrical system, comprising:

a first primary inductive connector that provides a first signal at a frequency between 1 and 100 megahertz;

a first secondary inductive connector that receives said first signal from said first primary inductive connector; and

,

first feedback means for monitoring a level of said first signal and generating a first feedback signal that is a function of said first signal level and which is transmitted from said secondary inductive connector to said primary inductive connector; and

,

power varying means for receiving said first feedback signal and varying said first signal level in response to said first feedback signal.

7. The system as recited in claim 6 further comprising a high pass filter operatively connected to said first secondary inductive connector to filter out frequencies below said first signal frequency.

8. The system as recited in claim 7, wherein said first feedback means includes;

voltage control oscillator means connected to said first secondary inductive connector for providing said first feedback signal which has a feedback frequency that is a function of said first signal voltage;

a second primary inductive connector connected to said voltage control oscillator means to transmit said first feedback signals;

a second secondary inductive connector coupled to said second primary inductive connector to receive said first feedback signals;

phase lock loop means connected to said second secondary inductive connector for receiving said first feedback signal and providing a power conversion signal with a power conversion signal voltage that is a function of said first feedback frequency;

amplifying means connected to said phase lock loop means and said first primary inductive connector for receiving said power conversion signal and controlling said first signal power provided by said first primary inductive connector as a function of said power conversion signal voltage.

9. A system comprising:

a first primary inductive connector that provides power at a power frequency;

a secondary primary inductive connector that provides a first signal at a first signal frequency and power, said first signal frequency being greater than said power frequency;

a first secondary inductive connector that receives said power from said first primary inductive connector;

a second secondary inductive connector that receives said first signal from said secondary primary inductive connector at a first signal voltage;

at least one high pass filter operatively connected to said second inductive connectors to filter out said power frequency;

first feedback means for monitoring a level of said power and generating a first feedback signal that is a function of said power level and which is transmitted from said first secondary inductive connector to said first primary inductive connector;

first power varying means for receiving said first feedback signal and varying said power level in response to said first feedback signal;

second feedback means for monitoring a level of said first signal and generating a second feedback signal that is a function of said first signal level and which is transmitted from said secondary inductive connector to said second primary inductive connector; and

second power varying means for receiving said second feedback signal and varying said first signal level in response to said second feedback signal.

10. The system as recited in claim 9, wherein said first feedback means and said first power varying means includes;

first voltage control oscillator means connected to said first secondary inductive connector for providing said first feedback signals to said first secondary inductive connector, said first feedback signals having a first feedback frequency that is different than said power frequency, said first voltage control oscillator means being adapted to vary said first feedback frequency as a function of said power level, said first feedback signals being transmitted from said first secondary inductive connector to said first primary inductive connector;

first phase lock loop means connected to said first primary inductive connector, for receiving said first feedback signals and providing a first power conversion signal that has a first power conversion signal voltage, said first power conversion signal voltage being dependent upon said first feedback frequency of said first feedback signals;

first automatic gain control means coupled to said first phase lock loop means and said first primary inductive connector for receiving said first power conversion signal and controlling said power provided by said first primary inductive connector as a function of said first power conversion signal voltage.

11. The system as recited in claim 10, wherein said first automatic gain control increases said power of said first primary inductive connector when said first conversion signal voltage is above a predetermined value, and decreases said power of said first primary inductive connector when said first conversion signal voltage is below a predetermined value.

12. The system as recited in claim 10, further comprising a first filter coupled to said first primary inductive connector and said first phase lock loop means to filter out said power provided by said first primary inductive connector from being received by said first phase lock loop means.

13. The system as recited in claim 9, wherein said second power varying means includes second automatic gain control means for receiving at least one second feedback signal, that is transmitted from said second secondary inductive connector to said second primary inductive connector, said second automatic gain control means controlling said first signal level as a function of said second feedback signal.

14. The system as recited in claim 13, wherein said second automatic gain control increases said first signal level when said second feedback is below a predetermined value, and decreases said first signal level when said second feedback signal is above a predetermined value.

15. The system as recited in claim 9, wherein said first primary and second secondary inductive connectors, and said first secondary and second primary inductive connectors each comprise;

a magnetic core with a base and at least two post extending from said base;

at least one power coil wrapped around said base between said post;

at least one signal coil wrapped around said post.

16. The system as recited in claim 9, further comprising a third primary inductive connector adapted to provide second signals at a second signal power and frequency, and a third secondary inductive connector adapted to receive said second signals from said third primary inductive connector at a second signal voltage, said second signal frequency being greater than said first signal frequency.

17. The system as recited in claim 16, further comprising a third high pass filter operatively connected to said third secondary inductive connector to filter out frequencies below said second signal frequency.

18. The system as recited in claim 16, further comprising third feedback means operatively connected to said third inductive connectors for controlling said second signal power of said third primary inductive connector as a function of said second signal voltage received by said third secondary inductive connector.

19. The system as recited in claim 18, wherein said third feedback means includes;

second voltage control oscillator means connected to said third secondary inductive connector for providing third feedback signals which have a third feedback frequency that is a function of said second signal voltage;

a fourth primary inductive connector connected to said second voltage control oscillator means to receive said third feedback signals;

a fourth secondary inductive connector coupled to said fourth primary inductive connector to receive said third feedback signals;

second phase lock loop means connected to said fourth secondary inductive connector for receiving said third feedback signal and providing a second power conversion signal with a second power conversion signal voltage that is a function of said third feedback frequency;

amplifying means connected to said second phase lock loop means and said third primary inductive connector for receiving said second power conversion signal and controlling said second signal power provided by said third primary inductive connector as a function of said second power conversion signal voltage.