US1980146A - Time switch device - Google Patents

Time switch device Download PDF

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Publication number
US1980146A
US1980146A US679810A US67981033A US1980146A US 1980146 A US1980146 A US 1980146A US 679810 A US679810 A US 679810A US 67981033 A US67981033 A US 67981033A US 1980146 A US1980146 A US 1980146A
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US
United States
Prior art keywords
resistance
circuit
condenser
capacity
switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US679810A
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English (en)
Inventor
Vingerhoets Antonius Wilhelmus
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Philips Gloeilampenfabrieken NV filed Critical Philips Gloeilampenfabrieken NV
Application granted granted Critical
Publication of US1980146A publication Critical patent/US1980146A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/38—Exposure time
    • H05G1/42—Exposure time using arrangements for switching when a predetermined dose of radiation has been applied, e.g. in which the switching instant is determined by measuring the electrical energy supplied to the tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
    • H03K17/28—Modifications for introducing a time delay before switching
    • H03K17/288—Modifications for introducing a time delay before switching in tube switches
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05G—X-RAY TECHNIQUE
    • H05G1/00—X-ray apparatus involving X-ray tubes; Circuits therefor
    • H05G1/08—Electrical details
    • H05G1/26—Measuring, controlling or protecting
    • H05G1/30—Controlling
    • H05G1/38—Exposure time

Definitions

  • the time of exposure has to be adjustable within certain limits, for instance, for exposure times varying between .1 second to 3 seconds.
  • the time devices having clock mechanism have a linear character. To provide them with a dial in which the graduation is non-linear, for instance, to provide them with a dial which has a logarithmic scale division, would be highly iml practical.
  • the blackening of the light-sensitive layers used for taking X-ray exposures varies substantially as a logarithmic function of the time.
  • Electrical time-switches in which the time interval is determined by the variation of an electric magnitude, which variation may be of a logarithmic function of time, can be obtained, for instance, by using the variation occurring in the conditions of charge of a condenser, whereby the time adjustments are obtained by varying the resistance or capacity of the circuit, or both.
  • the successive contacts of the switch can be at uniform distance from each other, or if a dial is provided for the switch, the dial can have a uniform scale for a logarithmic variation of the time.
  • the duration of the process is determined by the time interval required for an electrical magnitude to vary between two fixed values.
  • the charging of the condenser through a resistance is started, and by suitable interconnection of the charging circuit of the condenser with the grid of the tube, the grid potential is gradually reduced-according to an exponential function-during the charging of the condenser. After a given time interval the potential of the grid assumes a value which is insufficient to permit ignition of the discharge through the tube. This blocks the current flow in the anode circuit of the tube.
  • this 'Ihe anode circuit may comprise a relay switch which electrically controls the process.
  • this relay upon application of a suiciently positive potential to the grid, closes the primary circuit of the high voltage transformer and when the grid potential has been reduced to a value which is insuicient to ignite the discharge tube, the relay opens this circuit.
  • the duration of the process can be conveniently varied by making either the resistance or the condenser, or both, variable and by adjusting same to the desired values.
  • the relay tube instead of operating as a normally energized relay through which the current is interrupted during the time interval of control, may operate as a normally de-energized relay through which the current only fiows during the control time interval.
  • One object of my invention is to provide a time Switch device in which the successive contact steps to be passed by the switch member can be spaced apart at equal distances and at the same time the time intervals corresponding to the different contact positions of the switch may vary according to a logarithmic function.
  • a further object of my invention is to provide for a large number of adjustments without unduly increasing the number of resistance taps or without requiring a large regulating resistance.
  • a still further y object of my invention is to ⁇ provide a continuous progressive movement of the switch member to obtain increasing time intervals, whereby when passing from one capacity stage to the following capacity stage the time interval is increased by a step similar, to that between successive resistance stages of a given capacity stage.
  • a still further object of my invention is'to use a single regulating knob for varying the time interval, whereby for the first capacity stage the switch member successively passes all of the resistance stages and then switches in the second capacity stage and passes again 'all of the resistance stages, etc.
  • both the resistance and the capacity are made variable.
  • the switch is so arranged and interconnected that for a given capacity stage its switching member passes all ⁇ of the resistance stages and after having passed same, automatically connects the successive capacity stage for which it again passes all of the resistance stages, etc.
  • the resistance and capacity stages are computed in known manner, and it'suices here to state that the time interval t required for a voltage difference V, is proportional to the product RC loge V, where R and C are the values of the resistance and capacity included in the circuit.
  • the product RC is called the time constant of the circuit, and in the present instance determines the time adjustment of the time-switch.
  • the taps of the variable resistance are so selected that the value of the individual resistance stages'form a geometrical series.
  • Fig. 1 is a circuit diagram showing my novel time-switch in an arrangement in which the voltage variations of a discharging condenser is used for the control of the grid potential of the relay tube.
  • the relay or switching tube 2 is a three-electrode tube having an incandescible cathode 14, an anode 30 and a control electrodeA or grid 13.
  • the discharge tube 2 may be a high vacuum tube, but is preferably a gas-filled arc-discharge device.
  • a transformer winding 1 supplies the voltage for the anode circuit of the tube 2 between its tap 33 and its right end terminal 32.
  • the anode circuit includes the coil of a magnetic switch 8 which is connected between the winding terminal 32 and the anode 30; the cathode 14 connection to the tap 33 completes the anode circuit.
  • the cathode 14 is connected with its other end to the transformer tap 34.
  • the magnetic switch 8 controls the opening and closure of a contact 7 provided in the control-circuit of the process, the duration of which is to be controlled; for instance in the case of an X-ray installation it is inserted in the primary circuit of the high tension transformer. Normally the contact 7 is kept open by the bias of aV spring 36.
  • the switch '9 is a two-position switch with a wheel 39 and two contact positions I and II.
  • position I the condenser 3 is charged through the circuit including the winding portion 31-10, condenser 3, closed switch 9, rectier 4, and resistance 38.
  • the contact point II of the switch 9 is connected to the junction point of the resista/nce terminal 40 and of the grid 13, and when the switch is brought into position II the positive electrode of condenser 3 impresses upon the grid 13 a positive potential. This ignites the tube in the next positive half-cycle of the anode voltage and causes inthe positive half-cycles thereof a current flow through the anode circuit.
  • the condenser 3 gradually discharges over the circuit including the switch 9, contact II, portion of resistance 11, and switchmember 12, the positive bias on grid 13 diminishes until it reaches a value which is insuiiicient to ignite the tube (or in case of a high vacuum discharge tube which is insufficient to permit current flow) in the succeeding positive halfcycles of the anode voltage.
  • the relay 8 is de-energized, its contact 7 opened, and the process controlled by same is interrupted.
  • the time interval at which the grid potential falls to a value which blocks the anode current can be accurately adjusted to the desired value.
  • creasing portions of resistance 11 are connected in the circuit.
  • the combined capacity of the condensers 3 and 16 are connected in series with the resistance 11 and the time interval of discharge thus further increased.
  • the capacity of condenser 16 is so selected that its inclusion in the circuit provides a uniform variation of theI capacity resistance product when passing froma position in which condenser 3 is connected in series with the total resistance 11 to a position in which the parallel connected condensers 3 and 16 are connected in series with the first tap of resistance 11.
  • Fig. 2 shows an arrangement which differs from that of Fig. 1 in several respects. Instead of using the discharge voltage of the condenser to vary the grid bias, the charging voltage of the condenser is used therefor. Furthermore, to vary the time adjustment of the time switch a tapped resistor 23 is connected in series with different capacity values. Further differences will appear thereafter.
  • the anode circuit of the discharge tube 2 is the same as in Fig. 1.
  • the potential of grid 13 is normally negatively biased due to the electron emission of the cathode 5 of rectifier tube 4 with which it is electrically connected.
  • a wire 50 leading to a junction point 51 to which is connected wire 52 leading to the wheel 53 of a switch arm 22 of a switch A.
  • the arm 22 contacts with one of the twelvecontacts a, b, c, d, a', b', c', d', a, b, c", d", arranged in a circle around the heel 53 of the switch.
  • the condenser 3 is connected with one of its electrodes to the junction point 51 and with its other electrode to a junction point 44.
  • a three-position drum-controller 17 is provided and is shown in the drawing in its development.
  • the contactor 41 connects with the junction point 51, the contactor 42 with the junction point 44 and the contactor 43 with a tap 20 of the transformer winding 1, which tap lies between the tap 34 and the terminal 32 of the winding 1, close to tap 34.
  • the contact drum has three positions I, II and III and is provided with four contact segments.: a contact segment 18 contacts with contactor 41 in positions II and III; a segment 19, which contacts with contactor 42 in positions I. II and III. and two short segments 21 and 28, which contact with contactor 43 in the positions I and III respectively.
  • the time interval obtained depends on the position of contact arm 22.
  • contacts a, b, c and d, contacts a', b', c and d', and contacts a, b", c" and d" represent three groups of contacts, and it should beV well understood that both the number of contacts per group as well as the number of groups, can be conveniently increased.
  • the arm 22 is moved successively in a clockwise direction to contact with these contacts, increasing portions of the resistance 23 are connected in the charging circuit.
  • the Successive resistance portions or stages are .so selected as to form a geometric series. For instance, if the rst stage falling between points 60 and 61 has a Value r, the second stage falling between points-60 and 62 has'a value kr, the third stage falling between the points 60 and 63 has a value k2r, and the fourth stage falling between the points 60 and 64 has a value cr.
  • the parallel-connected condensers 3 and 25 are and 25, namely C1, Cz be k* times the capacity C1 of condenser 3.
  • the condenser 27 has such a capacityCa that the combined capacities Ci-i-Ca-i-Ca of condensers, 3, 25 and 27 respectively are equal to
  • the time constant for the position a" is krCl and the time constants for the positions b", c" and d" are k9rC1; A210101; and k11rC1 respectively.
  • the switch provides for twelve different switching times, the time corresponding to successive contacts being a fixed multiple of that corresponding to the preceding contact. Thisis in conformance with the actual requirements in practice as the time required for the blackening of sensitive layers follows a similar progression.
  • the position III of the contact drum provides forthe prolongation of the duration of the controlledprocess to any desired extent.
  • the connections of positions II and I are established.
  • the condenser 3, and alsothe condenser 25 and 27 if they are in parallel therewith, are shortcircuited and at the same time a positive potential is applied to the grid 13.
  • the device may be employed both for fixed short time intervals or for continuous use; when used, for instance, in connection with X-ray installations, the drum is brought into position II for short time exposure, as required in radiographic work, and into position III as required for continuous iluoroscopic work.
  • a time switch device comprising a discharge tube having an auxiliary electrode and means to vary the potential of said electrode in accordance with a varying condenser charge said means comprising an electric circuit, and means to vary the time constant of said circuit, said latter means comprising a variable resistance and a multi-stage capacity in series arrangement I4 in said circuit, and a switching means for progressively increasing, in successive stages, the resistance from a minimum to a maximum value, said switching means being arranged to connect an increased capacity stage in the circuit after having passed all of the resistance stages at the preceding capacity stage and to pass successively all of the resistance stages at said increased capacity stage.
  • a time switch device comprising an anode, a cathode and a control electrode, a current circuit including said anode and cathode and a second current circuit including a variable resistance and a variable capacity, a portion of said second current circuit being connected between said cathode and said control electrode, means in said second circuit for applying a unidirectional potential to said capacity and thereby applying to the control electrode a potential which, due to the change in charge of the capacity, assumes a value diiering from its initial value, one of said control-electrode potentials rendering the tube conductive, the other rendering it non-conductive, a switch member for regulating said resistance which, when moved from its initial position to its end position, passes at least one position in which it connects an increased capacity stage in said second circuit and before and after reaching said one position increases said variable resistance progressively from a minimum Value to a maximum value, without varying the capacity.
  • a time switch device comprising an anode, a cathode and a control electrode, a current circuit including said anode and cathode and a second current circuit including a variable resistance divided into n stages, the values of the resistances of said stages forming substantially a geometrical series, said second circuit further including a variable capacity, the values of the capacities of successive capacity stages corresponding to the n-th power of the ratio between the resistance values of two successive resistance stages, a portion of said second current circuit being connected between said cathode and said control electrode, means in said second circuit applying a unidirectional potential to said capacity and thereby applying to the control electrode a potential which, due to the change in the charge of the capacity in said second circuit, assumes a value diiering from its initial value, one of said control electrode potentials rendering the tube conductive, the other rendering it non-conductive, a switch member for regulating said resistance, which when moved from its initial position to its end position passes successively said n resistance stages without varying the capacity and then increasing the capacity to the next stage
  • a discharge tube having an anode, a cathode and at least one control electrode, an anode current circuit including said anode and cathode, a second circuit of which a portion is connected between saidv control electrode and said cathode and means in said second circuit ⁇ for establishing a potential difference between the cathode and control electrode varying from one predetermined value to a second predetermined value according to an exponential law, one of said values rendering the tube operative, the other rendering it inoperative, means for varying the time constant of said second circuit, said means comprising a variable resistance and a variable capacity both included in said second circuit and a switch device serving to regulate both said resistance and said capacity to include in the circuit each stage of the capacity with any of the resistance stages successively.
  • means for varying the time constant of said circuit comprising a variable resistance having n stages, the values of which form substantially a geometrical series with a ratio lc and a variable capacity having stages the capacity ofwhich have a ratio substantially equal to lc and a switch device to insert each capacity stage in combination with any of the resistance stages successively into the circuit, whereby the time ccnstants of the successive combinations form substantially a geometrical series.
  • An electric timing device comprising a gaslled discharge tube having an anode, a cathode and a control electrode, a source of alternating electromotive force supplying anode current to said tube, a plurality of condensers and a resistance having a plurality of stages, a switch device arranged to connect one of said condensers in series with any of the desired stages of the resistance and in multiple with any desired number of the other condensers, a rectifier and a second switch having two positions, said lastmentioned switch in one position closing a charging circuit from said source of electromotive force to a circuit including the condensers and resistance stage rendered effective by said rst switch device, and said rectifier, and in another position short-circuiting said condensers, the latter being connected to the control electrode which has, when the condensers are discharged, a potential at which the tube is operative and when they are charged to a denite voltage a potential at which the tube is inoperative.
  • a time switch device comprises a discharge tube having a cathode, an anode and a control electrode, a circuit of which a portion is connected between said cathode and said control electrode, means in said circuit for varying the potential of said control electrode to control said discharge tube and means for adjusting the time constant of said circuit, said adjusting means comprising capacity and resistance elements and a progressively movable switching means connected thereto in such a manner that upon movement from its initial position to its end position the resistance in the circuit is varied more than once from one predetermined magnitude to another while the capacity in the circuit is only changed between the periods of resistance variation.

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  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • X-Ray Techniques (AREA)
  • Motor And Converter Starters (AREA)
  • Generation Of Surge Voltage And Current (AREA)
US679810A 1932-07-05 1933-07-10 Time switch device Expired - Lifetime US1980146A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE414889X 1932-07-05

Publications (1)

Publication Number Publication Date
US1980146A true US1980146A (en) 1934-11-06

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US679810A Expired - Lifetime US1980146A (en) 1932-07-05 1933-07-10 Time switch device
US679811A Expired - Lifetime US2061011A (en) 1932-07-05 1933-07-16 Circuit arrangement for electrical time control

Family Applications After (1)

Application Number Title Priority Date Filing Date
US679811A Expired - Lifetime US2061011A (en) 1932-07-05 1933-07-16 Circuit arrangement for electrical time control

Country Status (4)

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US (2) US1980146A (xx)
FR (1) FR758018A (xx)
GB (2) GB407583A (xx)
NL (2) NL37240C (xx)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2471834A (en) * 1944-12-09 1949-05-31 Gen Electric Electronic relay
US2638731A (en) * 1948-05-01 1953-05-19 Deering Milliken Res Trust Control system
US2663003A (en) * 1949-04-16 1953-12-15 Sylvania Electric Prod Adjustable potentiometer
US2668909A (en) * 1950-04-10 1954-02-09 Exposure timer for x-ray apparatus
US2803814A (en) * 1945-07-30 1957-08-20 bloser
US2913056A (en) * 1956-10-01 1959-11-17 United Aircraft Corp Propeller control anticipator
US2941127A (en) * 1957-05-15 1960-06-14 Cutler Hammer Inc Electronic timing system
US2942151A (en) * 1957-08-16 1960-06-21 Westinghouse Electric Corp Electric discharge apparatus
US3324306A (en) * 1961-02-20 1967-06-06 Ncr Co Switch-operable bistable multivibrator unaffected by contact bounce

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2420919A (en) * 1942-07-10 1947-05-20 Weltronic Co Timing control system
US2537862A (en) * 1943-07-09 1951-01-09 Bell Telephone Labor Inc High-voltage pulse generator
US2459784A (en) * 1943-08-10 1949-01-25 John W Alderson Millivolt control unit
US2431284A (en) * 1943-11-20 1947-11-18 Westinghouse Electric Corp Pulsation timing system
US2423478A (en) * 1944-08-25 1947-07-08 Honeywell Regulator Co Condition control apparatus
US2560386A (en) * 1944-09-02 1951-07-10 Mcgraw Electric Co Automatic electric toaster
US2431195A (en) * 1944-10-09 1947-11-18 Mcgraw Electric Co Automatic electric toaster
US2560387A (en) * 1944-11-22 1951-07-10 Mcgraw Electric Co Automatic electric toaster
US2451508A (en) * 1944-11-22 1948-10-19 Mcgraw Electric Co Automatic electric toaster
US2560388A (en) * 1945-01-06 1951-07-10 Mcgraw Electric Co Automatic electric toaster
US2420188A (en) * 1945-01-06 1947-05-06 Mcgraw Electric Co Automatic electric toaster
US2415963A (en) * 1945-01-31 1947-02-18 Mcgraw Electric Co Automatic electric toaster
US2560389A (en) * 1945-03-02 1951-07-10 Mcgraw Electric Co Automatic electric toaster
US2542998A (en) * 1945-07-16 1951-02-27 Int Standard Electric Corp Matched potential control system
US2479274A (en) * 1946-01-04 1949-08-16 Gage B Ellis Timing circuit
US2448371A (en) * 1946-04-04 1948-08-31 Gen Electric Circuit making and breaking in response to power failure
US2461266A (en) * 1946-05-31 1949-02-08 Godwin R F Gay Timing device
US2494520A (en) * 1946-10-14 1950-01-10 Bendix Aviat Corp Electronic timer
US2657308A (en) * 1950-07-29 1953-10-27 Standard Telephones Cables Ltd Signal receiver circuit
US2761099A (en) * 1951-02-05 1956-08-28 Will F Wilson Intermittently operated motor for camera
US2840204A (en) * 1954-01-14 1958-06-24 Burroughs Corp Time delay device
US2779336A (en) * 1954-07-13 1957-01-29 Horace E Abbe Electro-therapeutic apparatus
US2898476A (en) * 1955-07-05 1959-08-04 Honeywell Regulator Co Transistor control apparatus
US2945185A (en) * 1957-11-19 1960-07-12 Western Electric Co Pulsing system
US3164723A (en) * 1958-03-11 1965-01-05 Philips Corp Voltage regulating circuit for x-ray tubes

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2471834A (en) * 1944-12-09 1949-05-31 Gen Electric Electronic relay
US2803814A (en) * 1945-07-30 1957-08-20 bloser
US2638731A (en) * 1948-05-01 1953-05-19 Deering Milliken Res Trust Control system
US2663003A (en) * 1949-04-16 1953-12-15 Sylvania Electric Prod Adjustable potentiometer
US2668909A (en) * 1950-04-10 1954-02-09 Exposure timer for x-ray apparatus
US2913056A (en) * 1956-10-01 1959-11-17 United Aircraft Corp Propeller control anticipator
US2941127A (en) * 1957-05-15 1960-06-14 Cutler Hammer Inc Electronic timing system
US2942151A (en) * 1957-08-16 1960-06-21 Westinghouse Electric Corp Electric discharge apparatus
US3324306A (en) * 1961-02-20 1967-06-06 Ncr Co Switch-operable bistable multivibrator unaffected by contact bounce

Also Published As

Publication number Publication date
GB407583A (en) 1934-03-22
NL39803C (xx)
FR758018A (xx) 1934-01-08
NL37240C (xx)
GB414889A (en) 1934-08-16
US2061011A (en) 1936-11-17

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