US2848659A - Electronic control switch - Google Patents

Electronic control switch Download PDF

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US2848659A
US2848659A US51465955A US2848659A US 2848659 A US2848659 A US 2848659A US 51465955 A US51465955 A US 51465955A US 2848659 A US2848659 A US 2848659A
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circuit
tube
switch
relay
touch
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Leon H Cutler
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General Electric Co
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General Electric Co
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/51—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used
    • H03K17/52—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of gas-filled tubes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H51/00—Electromagnetic relays
    • H01H51/02—Non-polarised relays
    • H01H51/04—Non-polarised relays with single armature; with single set of ganged armatures
    • H01H51/06—Armature is movable between two limit positions of rest and is moved in one direction due to energisation of an electromagnet and after the electromagnet is de-energised is returned by energy stored during the movement in the first direction, e.g. by using a spring, by using a permanent magnet, by gravity
    • H01H51/08—Contacts alternately opened and closed by successive cycles of energisation and de-energisation of the electromagnet, e.g. by use of a ratchet
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J17/00—Gas-filled discharge tubes with solid cathode
    • H01J17/02—Details
    • H01J17/30—Igniting arrangements

Definitions

  • This invention relates to an electric circuit control switch operable by touch contact; more particularly, it relates to an electric switch operable by touch contact with a pair of touch surfaces which provides reliable operation under a wide variety of external conditions.
  • a further object of the invention is to provide an electronic switch which avoids the buildup of a charge on circuit elements thereby preventing spurious operation.
  • the present invention comprises a switch operable by touch contact in which there is a glow tube having at least three electrodes, one of which is a control electrode, one a cathode, and one an anode; a latching relay having contacts which alternately open and close an external circuit upon energization of the relay; a capacitor in a circuit connecting the tube and relay in series and the capacitor in parallel therewith; a source of light in proximity to the glow tube; a first touch surface connected to the relay-tube-capacitor circuit at the potential of the anode side of the alternating current input; a second touch surface; and a high resistance circuit connecting the second touch surface to the control electrode of the glow tube, the circuit including high resistance branchconnections to the other two electrodes of the glow tube.
  • the switch illustrated diagrammatically in the drawing is intended to operate on alternating current of the normal 110-120 volt range and, therefore, the circuit is shown connected to a conventional plug although such a plug is not necessarily a part of the switch mechanism itself.
  • Half-wave rectification of the line voltage is achieved by means of a rectifier 20 which may be of the conventional selenium type, but other types are also satis- EQQ factory.
  • the line voltage is utilized to charge a capacitor 11, which is preferably of the electrolytic type, through a resistor 23.
  • the capacitor 11 is connected across a circuit comprising a miniature glow tube 12 and a latching relay 13 which alternately opens and closes an external circuit 14 upon energization.
  • the resistor 23 limits the rate of charging of the capacitor 11 to a safe value and, together with the capacitor, determines the retiring time in addition to which it limits current flow from the supply through the relay 13 and tube 12 when the capacitor 11 discharges.
  • the miniature glow tube 12 preferably has at least three elements consisting of a control electrode 15, a cathode 15a, and an anode 15b.
  • the tube 12 is desirably a miniature neon tube having in the envelope three electrodes of the same configuration with the control electrode 1S occupying an intermediate position which completely interrupts the line of sight between the cathode 15a and anode 15b.
  • the three electrodes can be composed of metallic rod material about a quarter-inch in length by about one thirty-second-inch in width. Normally, the few milliampere current-carrying capacity of the tube 12 is much too small to energize a relay. However, the tube may be overloaded sufficiently (i. e. 200 ma.) for a short interval to bring about momentary energization of a relay. Since the relay 13 is of the latching type, momentary energization thereof is sufficient to reverse the setting of its contacts.
  • the latching relay 13 has an armature 17 which is not a part of the external electrical circuit 14 but, nevertheless, eifectuates the mechanical movement which controls the circuit.
  • the actual circuit completing members are an immovable element 18 and a pair of spring biased elements 19 and 21, the elements 18 and 19 being equipped with contacting buttons 13a and 19a respectively.
  • the element 21 is equipped with a detent 22 which is engageable by the end of the attracted armature 17 when the contacts are in the open position illustrated. After engaging the detent 22, armature movement forces the element 21 out of engagement with the element 19 which brings into engagement the contacts 18a and 1% due to the spring bias of the element 19. At the same time, the tip of the element 15 engages the element 21 to hold the detent 22 out of the path of travel of the armature 17.
  • a control circuit for the tube 12 consists of a touch surface or plate 16 connected to the control electrode 15 through a trunk resistor 27.
  • a branch circuit connects the touch plate 16 to the cathode 15a through the branch resistor 29 which preferably, though not necessarily, has a stabilizing capacitor 31 in circuit therewith.
  • the anode 15b is connected to the touch surface 16 through a branch circuit including a resistor 28.
  • the tube 12 has a tendency to alter its characteristics in an erratic manner according to whether it is surrounded by light or darkness. Since this can result in spurious operation of the switch, a source of light 32 is connected across the line through a resistor 33. Since the source of light is always in operation, it is desirable that it be placed close to the tube 12 and operate on very low current. A miniature neon tube is satisfactory for this purpose both from the standpoint of initial cost, reliability, and low power consumption.
  • Spurious conduction of the tube 12 due to the gradual accumulation of a static charge on the surface 16 is avoided due to the fact that the branch circuits through the resistors 28 and 29 and capacitor 31 drain off such charge.
  • the circuit In operating the switch illustrated, the circuit is connected to a source of energy which charges the capacitor 11.
  • the circuit characteristics are such that breakdown voltage of the tube 12 is not attained.
  • anode potential is applied to the control electrode 15 to enable the tube 12 to become momentarily conducting, thereby energizing the relay 13 to change the setting of its contacts either to open or to close the circuit 14.
  • the external circuit 14 has not been shown in its entirety, it is obvious that any switch control function such as turning a lamp on and off or starting and stopping an electric motor or electronic apparatus could be brought about by the switch circuit illustrated.
  • the touch surfaces 16 and 25 do not have to have any particular configuration, but in most applications it is desirable that they be placed close to each other, as by interleaving, so that it is difficult to touch one without also touching the other. There is thus provided a switch which is particularly useful for persons who have lost the use of their fingers since mere contact of the touch surfaces 16 and 25 with the arm or any part of the body will effect operation of the switch.
  • circuit elements may be correlated for operation under widely varying voltage conditions. Such correlation of circuit components is within the realm of those skilled in the art and, therefore, the following listing of values for the resistors and capacitors of the circuit is intended to be illustrative without being limiting. The elements are identified by the numbers shown on the drawing.
  • Capacitors Number Capacitance 11 mfd 40 31 mmfd 700 While the invention has been discussed primarily with reference to the specific embodiment illustrated, there are many obvious modifications which fall within the spirit of the invention. Therefore, the invention is limited in scope only as may be necessitated by the scope of the appended claims.
  • a switch operable by touch contact comprising: a first glow tube having an anode, cathode, and control electrode; a latching relay connected to the cathode of said tube, said relay having. contacts adapted to control an external circuit; means for connecting the circuit formed by said tube and relay to a source of electrical energy; a capacitor connected across said tube and relay circuit; a second glow tube positioned to radiate light on said first glow tube; a first touch surface of conducting material connected through a high resistance to the anode of said first glow tube; and a second touch surface of conducting material in spaced relation with said first touch surface, said second touch surface being connected to all of the electrodes of said first glow tube through a branching circuit including a trunk resistor and additional resistors in the branch circuits leading to the cathode and anode, whereby touch contact with said touch surfaces effects conduction through said first glow tube when said switch is connected to a source of electrical potential- 2.
  • a switch operable by touch contact comprising: a glow tube having an anode, cathode, and control electrode; a latching relay energizable by a circuit through said glow tube; a capacitor to control the output from said glow tube to said relay; a source of light to radiate light on said glow tube; a first touch surface of conducting material connected as a ground plane for said switch; a second touch surface of conducting material in spaced relation to said first touch surface; and a circuit including a trunk resistor connecting said second touch surface to the control electrode of said glow tube, said circuit also including high resistance branch connections to the other two electrodes of said glow tube.
  • a switch operable by touch contact comprising: a glow tube having at least three electrodes one of which is a control electrode, one a cathode and one an anode; a latching relay having contacts which alternately open and close an external circuit upon energization of said relay; a capacitor; a circuit connecting said tube and relay in series and said capacitor in shunt of said tube and relay, whereby the charge upon said capacitor controls the output from said glow tube to said relay; a source of light to radiate light on said glow tube; a first touch surface connected to the anode of said tube at ground potential; a second touch surface; and a high resistance circuit connecting said second touch surface to the control electrode of said glow tube, said circuit including high resistance branch connections to the other two electrodes of said glow tube, whereby said glow tube becomes conducting to energize said relay when said switch is connected to a source of electrical energy and said touch surfaces are bridged by touch contact.

Description

Aug. 19, 1958 H, CUTLER 2,848,659
ELECTRONIC CONTROL SWITCH Filed June 10, 1955 in Men t 02'":
lean f7. Cari/en HAS A t t orvvgg United States Patent ELECTRONIC CONTROL SWITCH Leon H. Cutler, Milford, Conn, assignor to General Electric Company, a corporation of New York Application June 10, 1955, Serial No. 514,659
5 Claims. (Cl. 317149) This invention relates to an electric circuit control switch operable by touch contact; more particularly, it relates to an electric switch operable by touch contact with a pair of touch surfaces which provides reliable operation under a wide variety of external conditions.
In Harnden et al. application S. N. 497,242, filed March 28, 1955, which is assigned to the same assignee as the present application, there is described an electronically controlled switch in which a glow tube becomes conducting to energize a latching relay upon contact of a person with a touch surface. The present invention is directed to a switch of the same general type as that disclosed in the Harnden et a1. application. This invention is directed particularly toward additional circuit elements which confer greater reliability of operation upon the switch.
It is an object of the present invention to provide an electronic type circuit switch operable by touch contact which will operate reliably under almost all operating conditions to which the switch is likely to be subjected.
It is another object of the invention to provide a switch operable by touch contact wherein there are two touch areas, one of which serves as a ground plane.
It is a further object of the invention to provide a switch operable by touch contact wherein the dark sensitivity of an electronic element is prevented.
A further object of the invention is to provide an electronic switch which avoids the buildup of a charge on circuit elements thereby preventing spurious operation.
Other objects of the invention will become apparent from the following specification considered in conjunction with the appended drawing which is a diagrammatic view of the circuit whereby the switch of the present invention operates.
Briefly stated, in accordance with one of its embodiments, the present invention comprises a switch operable by touch contact in which there is a glow tube having at least three electrodes, one of which is a control electrode, one a cathode, and one an anode; a latching relay having contacts which alternately open and close an external circuit upon energization of the relay; a capacitor in a circuit connecting the tube and relay in series and the capacitor in parallel therewith; a source of light in proximity to the glow tube; a first touch surface connected to the relay-tube-capacitor circuit at the potential of the anode side of the alternating current input; a second touch surface; and a high resistance circuit connecting the second touch surface to the control electrode of the glow tube, the circuit including high resistance branchconnections to the other two electrodes of the glow tube.
The switch illustrated diagrammatically in the drawing is intended to operate on alternating current of the normal 110-120 volt range and, therefore, the circuit is shown connected to a conventional plug although such a plug is not necessarily a part of the switch mechanism itself. Half-wave rectification of the line voltage is achieved by means of a rectifier 20 which may be of the conventional selenium type, but other types are also satis- EQQ factory. The line voltage is utilized to charge a capacitor 11, which is preferably of the electrolytic type, through a resistor 23. The capacitor 11 is connected across a circuit comprising a miniature glow tube 12 and a latching relay 13 which alternately opens and closes an external circuit 14 upon energization. The resistor 23 limits the rate of charging of the capacitor 11 to a safe value and, together with the capacitor, determines the retiring time in addition to which it limits current flow from the supply through the relay 13 and tube 12 when the capacitor 11 discharges.
The miniature glow tube 12 preferably has at least three elements consisting of a control electrode 15, a cathode 15a, and an anode 15b. The tube 12 is desirably a miniature neon tube having in the envelope three electrodes of the same configuration with the control electrode 1S occupying an intermediate position which completely interrupts the line of sight between the cathode 15a and anode 15b. The three electrodes can be composed of metallic rod material about a quarter-inch in length by about one thirty-second-inch in width. Normally, the few milliampere current-carrying capacity of the tube 12 is much too small to energize a relay. However, the tube may be overloaded sufficiently (i. e. 200 ma.) for a short interval to bring about momentary energization of a relay. Since the relay 13 is of the latching type, momentary energization thereof is sufficient to reverse the setting of its contacts.
The latching relay 13 has an armature 17 which is not a part of the external electrical circuit 14 but, nevertheless, eifectuates the mechanical movement which controls the circuit. The actual circuit completing members are an immovable element 18 and a pair of spring biased elements 19 and 21, the elements 18 and 19 being equipped with contacting buttons 13a and 19a respectively.
The elements 19 and 21, which are biased in the direction of each other, have cooperating step-shaped ends whereby, in the open-contact position illustrated, the element 21 holds the element 19 out of contact with the element 18. The element 21 is equipped with a detent 22 which is engageable by the end of the attracted armature 17 when the contacts are in the open position illustrated. After engaging the detent 22, armature movement forces the element 21 out of engagement with the element 19 which brings into engagement the contacts 18a and 1% due to the spring bias of the element 19. At the same time, the tip of the element 15 engages the element 21 to hold the detent 22 out of the path of travel of the armature 17. On the next energization of the relay 13, the trip portion of the armature 17 misses the detent 22 and engages the element 19 to open the contacts and 19a and enable the element 22 to spring into locking position and maintain the contacts in open position. Other types of latching relay are available and may be substituted for the particular type illustrated.
A control circuit for the tube 12 consists of a touch surface or plate 16 connected to the control electrode 15 through a trunk resistor 27. A branch circuit connects the touch plate 16 to the cathode 15a through the branch resistor 29 which preferably, though not necessarily, has a stabilizing capacitor 31 in circuit therewith. The anode 15b is connected to the touch surface 16 through a branch circuit including a resistor 28.
It is desirable that in addition to the touch surface 16 there be another touch surface 25-preferably in spaced relation theretoto provide through a resistor 26 an electrical coupling to the anode of the tube 12 thereby avoiding the necessity of having the plug 10 always connected for the same polarity. In addition, by
coupling the touch surface 25 to the anode side of the source, the effect of the capacitance to ground of the person contacting the touch surface is no longer required and it is the conductivity (or impedance) of a person bridging the touch surfaces 16 and 25 which raises the potential of the control electrode 15 toward the anode 15b to render the tube 12 conducting. This, in etfcct, provides an artificial internal ground plane.
The tube 12 has a tendency to alter its characteristics in an erratic manner according to whether it is surrounded by light or darkness. Since this can result in spurious operation of the switch, a source of light 32 is connected across the line through a resistor 33. Since the source of light is always in operation, it is desirable that it be placed close to the tube 12 and operate on very low current. A miniature neon tube is satisfactory for this purpose both from the standpoint of initial cost, reliability, and low power consumption.
Spurious conduction of the tube 12 due to the gradual accumulation of a static charge on the surface 16 is avoided due to the fact that the branch circuits through the resistors 28 and 29 and capacitor 31 drain off such charge.
In operating the switch illustrated, the circuit is connected to a source of energy which charges the capacitor 11. The circuit characteristics are such that breakdown voltage of the tube 12 is not attained. When a person now touches the surfaces 16 and 25, anode potential is applied to the control electrode 15 to enable the tube 12 to become momentarily conducting, thereby energizing the relay 13 to change the setting of its contacts either to open or to close the circuit 14. While the external circuit 14 has not been shown in its entirety, it is obvious that any switch control function such as turning a lamp on and off or starting and stopping an electric motor or electronic apparatus could be brought about by the switch circuit illustrated. The touch surfaces 16 and 25 do not have to have any particular configuration, but in most applications it is desirable that they be placed close to each other, as by interleaving, so that it is difficult to touch one without also touching the other. There is thus provided a switch which is particularly useful for persons who have lost the use of their fingers since mere contact of the touch surfaces 16 and 25 with the arm or any part of the body will effect operation of the switch.
It is obvious that the circuit elements may be correlated for operation under widely varying voltage conditions. Such correlation of circuit components is within the realm of those skilled in the art and, therefore, the following listing of values for the resistors and capacitors of the circuit is intended to be illustrative without being limiting. The elements are identified by the numbers shown on the drawing.
Resistors Number Resistance (megohms) 23 0.0082 26 0.68 27 0.1 28 29 6.8 33 0.47
Capacitors Number: Capacitance 11 mfd 40 31 mmfd 700 While the invention has been discussed primarily with reference to the specific embodiment illustrated, there are many obvious modifications which fall within the spirit of the invention. Therefore, the invention is limited in scope only as may be necessitated by the scope of the appended claims.
What I claim as new and desire to secure by Letters Patent of the United States is: t
l. A switch operable by touch contact comprising: a first glow tube having an anode, cathode, and control electrode; a latching relay connected to the cathode of said tube, said relay having. contacts adapted to control an external circuit; means for connecting the circuit formed by said tube and relay to a source of electrical energy; a capacitor connected across said tube and relay circuit; a second glow tube positioned to radiate light on said first glow tube; a first touch surface of conducting material connected through a high resistance to the anode of said first glow tube; and a second touch surface of conducting material in spaced relation with said first touch surface, said second touch surface being connected to all of the electrodes of said first glow tube through a branching circuit including a trunk resistor and additional resistors in the branch circuits leading to the cathode and anode, whereby touch contact with said touch surfaces effects conduction through said first glow tube when said switch is connected to a source of electrical potential- 2. A switch operable by touch contact comprising: a glow tube having an anode, cathode, and control electrode; a latching relay energizable by a circuit through said glow tube; a capacitor to control the output from said glow tube to said relay; a source of light to radiate light on said glow tube; a first touch surface of conducting material connected as a ground plane for said switch; a second touch surface of conducting material in spaced relation to said first touch surface; and a circuit including a trunk resistor connecting said second touch surface to the control electrode of said glow tube, said circuit also including high resistance branch connections to the other two electrodes of said glow tube.
3. A switch operable by touch contact comprising: a glow tube having at least three electrodes one of which is a control electrode, one a cathode and one an anode; a latching relay having contacts which alternately open and close an external circuit upon energization of said relay; a capacitor; a circuit connecting said tube and relay in series and said capacitor in shunt of said tube and relay, whereby the charge upon said capacitor controls the output from said glow tube to said relay; a source of light to radiate light on said glow tube; a first touch surface connected to the anode of said tube at ground potential; a second touch surface; and a high resistance circuit connecting said second touch surface to the control electrode of said glow tube, said circuit including high resistance branch connections to the other two electrodes of said glow tube, whereby said glow tube becomes conducting to energize said relay when said switch is connected to a source of electrical energy and said touch surfaces are bridged by touch contact.
4. A switch operable by touch contact as claimed in claim 3 wherein there is means for rectifying an altermating current input to the capacitor-glow tube-relay circuit.
5. A switch operable by touch contact as claimed in claim 3 wherein there is a capacitor connected in parallel in the branch circuit leading from the second touch surface to the cathode of the glow tube.
References Cited in the file of this patent UNITED STATES PATENTS 1 ,5 3 5, 3 60
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Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2946956A (en) * 1958-08-28 1960-07-26 United Shoe Machinery Corp Body conductivity operated controls for electric devices
US2971136A (en) * 1956-02-23 1961-02-07 Cerberus G M B H Method of and arrangement for operating a glow relay
US3056907A (en) * 1958-10-16 1962-10-02 Hubbell Inc Harvey Touch controlled circuit
US3062343A (en) * 1959-03-20 1962-11-06 Norton Co Dry-contact limit switch for machine tools
US3080509A (en) * 1957-10-14 1963-03-05 Radio Cores Inc Relay
US3100010A (en) * 1959-02-17 1963-08-06 Hanes Hosiery Mills Company Device for straightening and aligning the points of knitwear looping machines
US3144592A (en) * 1961-04-28 1964-08-11 Westinghouse Electric Corp Arrangement for controlling circuit continuity
US3286131A (en) * 1964-07-13 1966-11-15 Ideal Ind Capacitor-operated scr line fault detector
US3286134A (en) * 1963-05-16 1966-11-15 Ideal Ind Touch control circuit
US3303397A (en) * 1964-07-13 1967-02-07 Ideal Ind Relay switching circuit
US3337778A (en) * 1963-11-21 1967-08-22 Radio Cores Inc Relay apparatus
DE1292221B (en) * 1967-04-14 1969-04-10 Braun Ag Automatic switching of electronic tuning aids
US3496381A (en) * 1968-05-10 1970-02-17 Stanley Works Proximity control guard plate
US3626288A (en) * 1969-10-27 1971-12-07 Victor R Bart Apparatus for detecting conductive material utilizing a vapor lamp
US3862432A (en) * 1972-03-17 1975-01-21 Magic Dot Inc Touch actuated electronic switch
US4531287A (en) * 1983-05-25 1985-07-30 U.S. Philips Corporation Automatically operating electric shaver
US5453644A (en) * 1991-10-17 1995-09-26 U.S. Philips Corporation Personal-care apparatus comprising a capacitive on/off switch
EP2254247A1 (en) * 2009-05-18 2010-11-24 Osram Gesellschaft mit Beschränkter Haftung Sensor circuit
US20130298406A1 (en) * 2012-05-11 2013-11-14 Yong Chen Razor with improved soothing effects during shaving

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL56246C (en) * 1940-02-16
US1535360A (en) * 1923-06-29 1925-04-28 Henry F Vickery Electric house or lighting circuit
US2037925A (en) * 1932-07-30 1936-04-21 Westinghouse Lamp Co Apparatus for measuring radiations
US2049376A (en) * 1931-12-21 1936-07-28 Gen Electric Electrical amplifying circuit
US2138731A (en) * 1935-02-28 1938-11-29 Invex Corp Detector circuits
US2427751A (en) * 1945-03-29 1947-09-23 Westinghouse Electric Corp Capacitor closed relay having reduced holding current
US2453267A (en) * 1945-03-07 1948-11-09 Peter F Rossmann Electromagnetic switching device
US2525768A (en) * 1947-08-16 1950-10-17 Otis Elevator Co Electronic tube with conductive coating
US2659533A (en) * 1951-01-27 1953-11-17 Monroe Calculating Machine Touch-responsive keyboard

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1535360A (en) * 1923-06-29 1925-04-28 Henry F Vickery Electric house or lighting circuit
US2049376A (en) * 1931-12-21 1936-07-28 Gen Electric Electrical amplifying circuit
US2037925A (en) * 1932-07-30 1936-04-21 Westinghouse Lamp Co Apparatus for measuring radiations
US2138731A (en) * 1935-02-28 1938-11-29 Invex Corp Detector circuits
NL56246C (en) * 1940-02-16
US2453267A (en) * 1945-03-07 1948-11-09 Peter F Rossmann Electromagnetic switching device
US2427751A (en) * 1945-03-29 1947-09-23 Westinghouse Electric Corp Capacitor closed relay having reduced holding current
US2525768A (en) * 1947-08-16 1950-10-17 Otis Elevator Co Electronic tube with conductive coating
US2659533A (en) * 1951-01-27 1953-11-17 Monroe Calculating Machine Touch-responsive keyboard

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2971136A (en) * 1956-02-23 1961-02-07 Cerberus G M B H Method of and arrangement for operating a glow relay
US3080509A (en) * 1957-10-14 1963-03-05 Radio Cores Inc Relay
US2946956A (en) * 1958-08-28 1960-07-26 United Shoe Machinery Corp Body conductivity operated controls for electric devices
US3056907A (en) * 1958-10-16 1962-10-02 Hubbell Inc Harvey Touch controlled circuit
US3100010A (en) * 1959-02-17 1963-08-06 Hanes Hosiery Mills Company Device for straightening and aligning the points of knitwear looping machines
US3062343A (en) * 1959-03-20 1962-11-06 Norton Co Dry-contact limit switch for machine tools
US3144592A (en) * 1961-04-28 1964-08-11 Westinghouse Electric Corp Arrangement for controlling circuit continuity
US3286134A (en) * 1963-05-16 1966-11-15 Ideal Ind Touch control circuit
US3337778A (en) * 1963-11-21 1967-08-22 Radio Cores Inc Relay apparatus
US3286131A (en) * 1964-07-13 1966-11-15 Ideal Ind Capacitor-operated scr line fault detector
US3303397A (en) * 1964-07-13 1967-02-07 Ideal Ind Relay switching circuit
DE1292221B (en) * 1967-04-14 1969-04-10 Braun Ag Automatic switching of electronic tuning aids
US3496381A (en) * 1968-05-10 1970-02-17 Stanley Works Proximity control guard plate
US3626288A (en) * 1969-10-27 1971-12-07 Victor R Bart Apparatus for detecting conductive material utilizing a vapor lamp
US3862432A (en) * 1972-03-17 1975-01-21 Magic Dot Inc Touch actuated electronic switch
US4531287A (en) * 1983-05-25 1985-07-30 U.S. Philips Corporation Automatically operating electric shaver
US5453644A (en) * 1991-10-17 1995-09-26 U.S. Philips Corporation Personal-care apparatus comprising a capacitive on/off switch
EP2254247A1 (en) * 2009-05-18 2010-11-24 Osram Gesellschaft mit Beschränkter Haftung Sensor circuit
US20130298406A1 (en) * 2012-05-11 2013-11-14 Yong Chen Razor with improved soothing effects during shaving

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