Touch actuated electronic switch

• US 3,909,625 A
• Filed: 07/30/1973
• Issued: 09/30/1975
• Est. Priority Date: 07/30/1973
• Status: Expired due to Term

• Current Assignee: David E. Colglazier, Willis A. Larson
• Original Assignee: David E. Colglazier, Willis A. Larson
• Inventors: Colglazier, David E., Larson, Willis A.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Ginsburg, M.
• Application Number:
  US05/383,466
• Time in Patent Office: 792 Days
• Field of Search: 307/117,116,205,208 340/258C 200/DIG.1 317/DIG.2,246 328/1,5
• US Class Current: 307/116
• CPC Class Codes: H03K 17/962 Capacitive touch switches

Abstract

A touch actuated electronic switch is disclosed including at least one surface, accessible to the touch of a human, interconnected with differential sensing circuitry, in this application dual input logic circuitry. In the preferred embodiment where the interconnection between the logic circuit and the surfaces is desired to include long wires, a twisted pair of wires is used if increased noise immunity or noise protection is desired. The twisted pair is interconnected at one end with one wire electrically connected to the touch surface and the other substantially equal length wire being unconnected or connected to a second touch surface. Both wires are connected at their other ends to the dual inputs to the logic circuitry. A common mode alternating voltage signal is then provided through input circuitry to the logic circuitry, and the output of the logic circuitry is interconnected to an integrator, in the preferred embodiment a capacitor. The integrator is, in turn in the preferred embodiment, connected to an additional amplifier. The output terminals of the additional amplifier, in the preferred embodiment, act as an electrical switch with the electrical impedance across the output terminals in a first state assuming a high impedance, electrical open circuit, or '"'"''"'"''"'"''"'"'OFF'"'"''"'"''"'"''"'"' switch condition and in the second state assuming a low impedance, electrical short circuit, or '"'"''"'"''"'"''"'"'ON'"'"''"'"''"'"''"'"' switch condition to thereby approximate the two states of a conventional mechanical electrical switch, the condition assumed by the second amplifier being dependent upon whether or not an operator has touched a touch surface.

Claims

1. A touch actuated electronic switch, comprising in combination:

logic means including first signal input means and second signal input means for receiving signals to be compared and including signal output means for providing an output signal related to the differences in the input signal received;

at least one touch surface;

means for providing an electrical connection between the touch surface and an input means of the logic means;

means for receiving an alternating voltage signal;

means for providing an electrical connection between the receiving means and the logic means to provide a substantially balanced alternating voltage signal to the first and the second signal input means of the logic means;

integrating means; and

means for providing an electrical connection between the output means of the logic means and the integrating means.

2. The touch actuated electronic switch of claim 1, including impedance means connected as a shunting element between the input means of the logic means to provide increased noise suppression and sensitivity control.

3. The touch actuated electronic switch of claim 1, including amplifier means including signal input means for receiving a signal to be amplified and signal output means for providing an amplified signal output;

and means for providing an electrical connection between the integrating means and the input means of the amplifier means.

4. The touch actuated electronic switch of claim 1, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

5. The touch actuated electronic switch of claim 4, wherein the impedance means comprise resistors.

6. The touch actuated electronic switch of claim 1, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

7. The touch actuated electronic switch of claim 6 wherein the first impedance means and the second impedance means comprise resistors.

8. The touch actuated electronic switch of claim 1, wherein the logic means comprises an exclusive OR logic circuit.

9. The touch actuated electronic switch of claim 8, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

10. The touch actuated electronic switch of claim 8, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

11. The touch actuated electronic switch of claim 1, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

12. The touch actuated electronic switch of claim 11, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

13. The touch actuated electronic switch of claim 12, wherein the impedance means comprise resistors.

14. The touch actuated electronic switch of claim 11, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

15. The touch actuated electronic switch of claim 11, including impedance means connected as a shunting element between the input means of the logic means to provide increased noise suppression and sensitivity control.

16. The touch actuated electronic switch of claim 15, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

17. The touch actuated electronic switch of claim 11, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at powEr frequencies.

18. The touch actuated electronic switch of claim 1, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

19. The touch actuated electronic switch of claim 18, including impedance means connected as a shunting element between the input means of the logic means to provide increased noise suppression and sensitivity control.

20. The touch actuated electronic switch of claim 18, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

21. The touch actuated electronic switch of claim 18, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

22. The touch actuated electronic switch of claim 18, wherein the logic means comprises an exclusive OR logic circuit.

23. The touch actuated electronic switch of claim 22, wherein the means for providing an electrical connection between the touch surface and an input to the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

24. The touch actuated electronic switch of claim 23, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

25. The touch actuated electronic switch of claim 24, wherein the first impedance means and the second impedance means comprise resistors.

26. The touch actuated electronic switch of claim 18, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

27. The touch actuated electronic switch of claim 26, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

28. The touch actuated electronic switch of claim 1, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

29. The touch actuated electronic switch of claim 28, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first enD connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

30. The touch actuated electronic switch of claim 29, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

31. The touch actuated electronic switch of claim 30, wherein the logic means comprises an exclusive OR logic circuit.

32. The touch actuated electronic switch of claim 30, including impedance means connected as a shunting element between the input means of the logic means to provide increased noise suppression and sensitivity control.

33. The touch actuated electronic switch of claim 28, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

34. The touch actuated electronic switch of claim 33, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

35. A touch actuated electronic switch, comprising in combination:

exclusive OR logic means including first signal input means and second signal input means for receiving signals to be compared and including signal output means for providing an output signal related to the differences in the input signal received;

at least one touch surface;

means for providing an electrical connection between the touch surface and an input means of the logic means;

means for receiving an alternating voltage signal; and

means for providing an electrical connection between the receiving means and the logic means to provide a substantially balanced alternating voltage signal to the first and the second signal input means of the logic means.

36. The touch actuated electronic switch of claim 35, including:

integrating means; and

means for providing an electrical connection between the output means of the logic means and the integrating means.

37. The touch actuated electronic switch of claim 36, wherein the integrating means includes a capacitor and wherein the means for providing an electrical connection between the output means of the logic means and the integrating means includes unidirectional conduction means.

38. The touch actuated electronic switch of claim 36, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

39. The touch actuated electronic switch of claim 38, wherein the impedance means comprise resistors.

40. The touch actuated electronic switch of claim 36, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means, an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

41. The touch actuated electronic switch of claim 36, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

42. The touch actuated electronic switch of claim 36, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

43. The touch actuated electronic switch of claim 36, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

44. The touch actuated electronic switch of claim 35, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

45. The touch actuated electronic switch of claim 44, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

46. The touch actuated electronic switch of claim 44, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

47. The touch actuated electronic switch of claim 46, wherein the impedance means comprise resistors.

48. The touch actuated electronic switch of claim 44, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

49. The touch actuated electronic switch of claim 48, whErein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

50. The touch actuated electronic switch of claim 44, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

51. The touch actuated electronic switch of claim 44, including:

integrating means including a capacitor; and

means for providing an electrical connection between the output means of the logic means and the integrating means including unidirectional conduction means.

52. The touch actuated electronic switch of claim 35, wherein the logic means comprises MOS semiconductor devices to thereby provide a significant threshold for the switch.

53. The touch actuated electronic switch of claim 52, including:

integrating means including a capacitor; and

means for providing an electrical connection between the output means of the logic means and the integrating means including unidirectional conduction means.

54. The touch actuated electronic switch of claim 53, wherein the means for providing an electrical connection between the receiving means and the logic means includes first impedance means connected to the first signal input means and second impedance means connected to the second signal input means with the first and the second impedances having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means.

55. The touch actuated electronic switch of claim 54, wherein the impedance means comprise resistors.

56. The touch actuated electronic switch of claim 52, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

57. The touch actuated electronic switch of claim 56, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

58. The touch actuated electronic switch of claim 52, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.

59. The touch actuated electronic switch of claim 58, wherein the first impedance means and the second impedance means comprise resistors.

60. The touch actuated electronic switch of claim 58, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

61. The touch actuated electronic switch of claim 58, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second siGnal input means of the logic means for better providing noise immunity and remote actuation for the switch.

62. The touch actuated electronic switch of claim 35, wherein the means for receiving an alternating voltage signal comprises means for receiving an alternating voltage signal at power frequencies.

63. The touch actuated electronic switch of claim 62, including:

integrating means including a capacitor; and

means for providing an electrical connection between the output means of the logic means and the integrating means including unidirectional conduction means.

64. The touch actuated electronic switch of claim 63, wherein the means for providing an electrical connection between the touch surface and an input means of the logic means comprises a twisted pair of wires with the twisted pair having a first end and a second end and with one wire of the first end connected to the first signal input means of the logic means and the second wire of the first end connected to the second signal input means of the logic means for better providing noise immunity and remote actuation for the switch.

65. The touch actuated electronic switch of claim 62, wherein the means for providing an electrical connection between the receiving means and the logic means comprises:

first impedance means and second impedance means with the first impedance means and the second impedance means having values which are balanced to provide the substantially balanced alternating voltage signal to the first and second signal input means of the logic means;

an electrical junction point;

means for electrically connecting the first impedance means between the junction point and the first input means of the logic means;

means for electrically connecting the second impedance means between the junction point and the second input means of the logic means; and

means for providing an electrical connection between the junction point and the means for receiving the alternating voltage signal.