Disconnection arc prevention in cable-supplied power connection
Power delivery may be controlled to help prevent arcing when a data cable supplying power from a power source device to a power sink device is disconnected. The presence of a user in proximity to a connection between a cable plug and a cable receptacle may be detected. The level of a power signal being conveyed from the power source to the power sink may be reduced in response to the detection.
1. A method for controlling power of a data cable assembly, comprising:
a sensor detecting presence of a user in proximity to a connection between a cable plug and a cable receptacle, the cable plug and sensor being part of the data cable assembly, the data cable assembly further comprising a cable portion coupled to the plug, the sensor being housed within the cable plug;
generating a detection signal by the sensor in response to detecting the presence; and
reducing a level of a power signal being conveyed between the cable plug and the cable receptacle in response to the detection signal.
2. The method of claim 1 , wherein the cable plug and cable receptacle are configured for Universal Serial Bus (USB) power delivery.
3. The method of claim 1 , wherein reducing the level of the power signal comprises reducing the level of the power signal from a first level to a second non-zero level.
4. The method of claim 1 , wherein detecting the presence of the user comprises detecting the presence of the user in proximity to the connection at a power source device.
5. The method of claim 1 , further comprising transmitting the detection signal over the cable portion and the cable plug.
6. The method of claim 5 , wherein:
detecting the presence of the user comprises detecting the presence of the user in proximity to the connection at a power sink device; and
transmitting the detection signal comprises transmitting the detection signal to a power source device over the cable portion.
7. The method of claim 1 , wherein detecting the presence of the user comprises detecting a touch of the user.
8. The method of claim 7 , wherein detecting the touch of the user comprises detecting the touch of the user on a portion of the cable plug.
9. The method of claim 7 , wherein detecting the touch of the user comprises detecting the touch of the user on a portion of the cable receptacle.
10. The method of claim 1 , wherein detecting the presence of the user comprises detecting a non-zero proximity of the user.
11. The method of claim 10 , wherein detecting the non-zero proximity of the user comprises detecting the non-zero proximity of the user to a portion of the cable plug.
12. The method of claim 10 , wherein detecting the non-zero proximity of the user comprises detecting the non-zero proximity of the user to a portion of the cable receptacle.
13. The method of claim 1 , further comprising filtering the power signal using snubber circuitry in at least one of: the cable plug, a power source device providing the power signal, and a power sink device receiving the power signal.
14. The method of claim 13 , wherein the snubber circuitry comprises a capacitor and a resistor in series with each other.
15. The method of claim 13 , wherein the snubber circuitry comprises a diode.
16. A system for power control in a data cable assembly, comprising:
a cable containing one or more data signal paths and at least one power conductor;
a cable plug attached to an end of the cable, the cable and cable plug forming the data cable assembly;
a sensor housed in the cable plug configured to detect presence of a user in proximity to the cable plug; and
a power delivery controller housed in the cable plug configured to transmit via the cable plug a power level reduction signal in response to detecting the presence of a user in proximity to the cable plug.
17. The system of claim 16 , wherein the cable plug is configured for Universal Serial Bus (USB) power delivery.
18. The system of claim 16 , wherein the sensor is a touch sensor.
19. The system of claim 16 , wherein the sensor is a non-zero proximity sensor.
20. The system of claim 16 , further comprising snubber circuitry coupled to a power conductor of the cable portion.
21. The system of claim 20 , wherein the snubber circuitry comprises a capacitor and a resistor in series with each other.
22. The system of claim 20 , wherein the snubber circuitry comprises a diode.
23. The system of claim 16 , further comprising:
a power source cable receptacle mateable with the cable plug;
a power supply; and
a source power controller configured to receive the power level reduction signal and to reduce a level of a power signal provided by the power supply to the power source cable receptacle in response to the power level reduction signal.
24. The system of claim 23 , wherein the source power controller is configured to reduce the level of the power signal from a first level to a second non-zero level.
25. A system for cable-supplied power control in a power sink device, comprising:
a power sink cable receptacle having a data port and control channel port;
a sensor housed within the cable receptacle configured to detect presence of a user in proximity to the power sink cable receptacle; and
a sink power controller coupled to the control channel port and housed within the power sink device configured to transmit via the control channel port of the power sink cable receptacle a power level reduction signal in response to the sensor detecting the presence of a user in proximity to the power sink cable receptacle.
26. The system of claim 25 , wherein the power sink cable receptacle is configured for Universal Serial Bus (USB) power delivery.
27. The system of claim 25 , wherein the sensor is a touch sensor.
28. The system of claim 25 , wherein the sensor is a non-zero proximity sensor.
29. The system of claim 25 , further comprising snubber circuitry coupled to a power conductor of the power sink cable receptacle.
30. The system of claim 29 , wherein the snubber circuitry comprises a capacitor and a resistor in series with each other.
31. The system of claim 29 , wherein the snubber circuitry comprises a diode.
32. The system of claim 25 , further comprising a power source cable receptacle mateable with a cable;
a power supply; and
a source power controller configured to receive the power level reduction signal via the cable and the power source cable receptacle and to reduce a level of a power signal provided by the power supply to the power source cable receptacle in response to the power level reduction signal.
33. The system of claim 32 , wherein the source power controller is configured to reduce the level of the power signal from a first level to a second non-zero level.
34. A system for cable-supplied power control in a power source device, comprising:
a power source cable receptacle having a data port and control channel port;
a sensor housed within the cable receptacle configured to detect presence of a user in proximity to the power source cable receptacle;
a power supply; and
a source power controller coupled to the control channel port and housed within the power source device configured to reduce a level of a power signal provided by the power supply to the power source cable receptacle in response to the sensor detecting the presence of a user in proximity to the power source cable receptacle.
35. The system of claim 34 , wherein the power source cable receptacle is configured for Universal Serial Bus (USB) power delivery.
36. The system of claim 34 , wherein the sensor is a touch sensor.
37. The system of claim 34 , wherein the sensor is a non-zero proximity sensor.
38. The system of claim 34 , further comprising snubber circuitry coupled to a power conductor of the power sink cable receptacle.
39. The system of claim 38 , wherein the snubber circuitry comprises a capacitor and a resistor in series with each other.
40. The system of claim 38 , wherein the snubber circuitry comprises a diode.
41. The system of claim 34 , wherein the source power controller is configured to reduce the level of the power signal from a first level to a second non-zero level.