Granted Patent B2

US 6,968,049 · App. 10/252,738 · Granted Nov 22, 2005

Abstract

Claims (26)

1. A method for transmitting charging signals at a transmission frequency on a data transmission path, the method comprising:

determining an output current produced by a driver device;

determining a transfer function of the data transmission path at the transmission frequency;

providing a nominal value;

modifying the output current to match the nominal value with an output signal corresponding to a predetermined line voltage level;

causing the driver device to provide a driver output voltage level that defines the line voltage level; and

providing an amplifier circuit in the driver device, the amplifier circuit having a frequency-dependent gain factor for maintaining a constant predetermined line voltage level at the transmission frequency.

2. The method of claim 1 , further comprising selecting the charging signals to be sinusoidal signals.

3. The method of claim 1 , further comprising selecting the transmission frequency from the group consisting of 16 kHz and 12 kHz.

4. The method of claim 1 , wherein causing the driver device to provide a driver output voltage level comprises causing the driver output voltage level to be independent of a line impedance of the data transmission path.

5. The method of claim 1 , wherein providing an amplifier circuit comprises providing an amplifier with a feedback loop that includes a feedback resistive element and a feedback reactive element.

6. The method of claim 1 , wherein causing the driver device to provide a driver output voltage level comprises producing a predetermined overall voltage drop.

7. The method of claim 1 , further comprising producing a predetermined filter parallel current.

8. The method of claim 1 , further comprising producing a predetermined filter series current.

9. An apparatus for transmitting charging signals on a data transmission path having a line impedance, the apparatus comprising:

a driver device for setting a line voltage level that corresponds to the line impedance, the driver device configured to provide, in response to a driver input voltage level, a driver output current and a driver output voltage level;

a current detection unit that provides a current signal indicative of the driver output current;

a current signal matching unit for receiving the current signal from the current detection unit and adjusting a level of the current signal for further processing by a filter device and by a regulation device; and

a matching filter unit for matching the driver device to a data transmission path unit.

10. The apparatus of claim 9 , wherein the driver device comprises an amplifier unit.

11. The apparatus of claim 10 , wherein the amplifier unit comprises a feedback branch having a feedback resistance element and a feedback reactive element.

12. The apparatus of claim 11 , wherein the feedback resistance element and the feedback reactive element comprise passive elements.

13. The apparatus of claim 11 , wherein the feedback resistance element and the feedback reactive element comprise active elements.

14. The apparatus of claim 9 , wherein the current detection unit comprises a Hall sensor.

15. The apparatus of claim 9 , wherein the current detection unit comprises a shunt resistance element having a tap for a voltage drop that is proportional to the driver output current.

16. The apparatus of claim 9 , wherein the current signal matching unit comprises a voltage divider.

Assignments (9)