Patent US40662A successfully refreshed from Google Patents.
Patent US3679910A successfully refreshed from Google Patents.
US3679910A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Touch control switch
Assignee: Massachusetts Institute of Technology
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Filing: 1971-04-13
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Granted: 1972-07-25
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Expires: 1991-04-13
Abstract
Abstract A circuit which is responsive to sixty cycle voltage coupled to the circuit by a human body from a proximate 60 cycle power line. An input terminal when touched by a person''s finger has coupled into it a 60 cycle voltage which is amplified and causes the electronic circuitry to assume either a conducting or nonconducting state at its output which is maintained after removal of the finger from the terminal. The output of the circuit is connected to a controlled device which is controlled by the circuit output state.
Inventors
- 👤 James M Williams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:17
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/96; H03K17/962
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
236 words
An electrical switch responsive to the body-capacity coupled sixty cycle electric field of adjacent electrical power sources comprising: a high gain amplifier having an input and an output terminal, an electrical network, said amplifier output terminal being connected to said electrical network which has a time constant of the order of the period of the sixty cycle electric field; said amplifier and network being responsive to a sixty cycle signal applied to the amplifier input terminal to provide a step change in voltage in one direction at the output of said network when the signal is applied, with constant output voltage while said input signal is applied without interruption, and a step change in voltage in the opposite direction when said signal is removed; a bistable circuit connected to said network output and responsive to said step change in voltage to change its state only when said netwOrk output voltage changes in said one direction, and non-responsive to changes in the opposite direction or during the time said input signal is applied without interruption; said bistable circuit having an output connected to the input of a voltage controllable switch whose conductivity at the output terminal is determined by the state of the bistable circuit to which it is connected; whereby an electrical load connected to the switch output terminal is energized when said switch is electrically conductive as determined by the state of the bistable circuit.
Claim 2
Dependent Claim
236 words
An electrical switch responsive to the body-capacity coupled sixty cycle electric field of adjacent electrical power sources comprising: a high gain amplifier having an input and an output terminal, an electrical network, said amplifier output terminal being connected to said electrical network which has a time constant of the order of the period of the sixty cycle electric field; said amplifier and network being responsive to a sixty cycle signal applied to the amplifier input terminal to provide a step change in voltage in one direction at the output of said network when the signal is applied, with constant output voltage while said input signal is applied without interruption, and a step change in voltage in the opposite direction when said signal is removed; a bistable circuit connected to said network output and responsive to said step change in voltage to change its state only when said netwOrk output voltage changes in said one direction, and non-responsive to changes in the opposite direction or during the time said input signal is applied without interruption; said bistable circuit having an output connected to the input of a voltage controllable switch whose conductivity at the output terminal is determined by the state of the bistable circuit to which it is connected; whereby an electrical load connected to the switch output terminal is energized when said switch is electrically conductive as determined by the state of the bistable circuit.
Claim 3
Dependent Claim
41 words
The apparatus of claim 1 wherein said high gain amplifier and said bistable circuit are connected to a low direct voltage source of several volts whereby said switch circuit is rendered insensitive to spurious electrical signals present in the switch environment.
Claim 4
Dependent Claim
40 words
The apparatus of claim 1 wherein said electrical network comprises a capacitor connected across the output of said amplifier, said amplifier having an output resistance which in conjunction with said capacitor produces an output network having the desired time constant.
Claim 5
Dependent Claim
34 words
The apparatus of claim 1 wherein said voltage controllable switch is a semiconductor controlled rectifier whose input is connected to the output of said multivibrator and whose output is connected to an electrical load.
Claim 6
Dependent Claim
55 words
The apparatus of claim 1 wherein said electrical network comprises a capacitor connected across the output of said amplifier, said amplifier having an output resistance which in conjunction with said capacitor produces an output network having the desired time constant, and said bistable circuit is a bistable multivibrator whose input is connected to said capacitor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |