US2647208A - Electric circuit-arrangement - Google Patents

Electric circuit-arrangement Download PDF

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Publication number
US2647208A
US2647208A US216487A US21648751A US2647208A US 2647208 A US2647208 A US 2647208A US 216487 A US216487 A US 216487A US 21648751 A US21648751 A US 21648751A US 2647208 A US2647208 A US 2647208A
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US
United States
Prior art keywords
voltage
circuit
trigger
grid
control
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
US216487A
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English (en)
Inventor
Jager Frank De
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Hartford National Bank and Trust Co
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Hartford National Bank and Trust Co
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Publication date
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    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/04—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of vacuum tubes only, with positive feedback
    • H03K3/05—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of vacuum tubes only, with positive feedback using means other than a transformer for feedback
    • H03K3/06—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of vacuum tubes only, with positive feedback using means other than a transformer for feedback using at least two tubes so coupled that the input of one is derived from the output of another, e.g. multivibrator
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C3/00—Angle modulation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K3/00—Circuits for generating electric pulses; Monostable, bistable or multistable circuits
    • H03K3/02—Generators characterised by the type of circuit or by the means used for producing pulses
    • H03K3/04—Generators characterised by the type of circuit or by the means used for producing pulses by the use, as active elements, of vacuum tubes only, with positive feedback
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/02—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation
    • H04B14/04—Transmission systems not characterised by the medium used for transmission characterised by the use of pulse modulation using pulse code modulation
    • H04B14/042—Special circuits, e.g. comparators
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying
    • H04L27/12—Modulator circuits; Transmitter circuits

Definitions

  • This invention relates to trigger circuit-arrangements comprising at least two grid-controlled amplifying tubes cutting ofi each other by mutual feedback, the trigger circuit selecting one of two states of equilibrium in accordance with a control-voltage supplied thereto. In one state of equilibrium, one of the tubes passes cur.- rent and the other is cut off, and in the other state of equilibrium the anode current conditions of the trigger are reversed.
  • Such trigger circuits are widely used in prac "tice. They may, for example, be used for bilateral limitation or as a non-linear amplifier of a control-voltage supplied to a control-grid of one Across the output circuit of the trigger circuit is produced a rectangular voltage which, for example, is positive depending on whether the control-voltage exceeds or does not exceed a particular critical value, so that the trigger circuit gets into one or the otherstate
  • the difierence between control- ,voltages required to trip the trigger in different directions in other words the response sensitiveness when using conventional amplifying tubes, for example triodes or pentodes, is approximately 1 to 2 volts. 7
  • the object of the present invention is toprovide improved trigger circuits of the type referred to.
  • a common part of the grid circuits of the two amplifying tubes comprises a grid bias supply, driving the tubes into equal anode-current conditions irrespective- 1y of the control-voltage, and a switch-pulse generator connected in series with the said supply.
  • a third state of equilibrium of the trigger circuit is brought about in which either the two tubes of the trigger-circuit are non-conductive or the two tubes pass the full anode current.
  • trigger circuits according to the invention may be used for or adapted to various purposes, as will be set out In order that the invention may be readily. carried into effect, three examples will now be described in detail with reference to the accompanying drawings, in which:
  • Fig. 1 shows a trigger circuit according to the invention, comprising two cross-wise coupled pentodes
  • Fig. 2 shows static characteristic curves asso ciated with the circuit depicted in Fig. 1, which indicate the relationship existing between, the switch-voltage and the output voltage. of the trigger circuit at various valuesof the controlvoltage;
  • Fig. 3 shows the circuit according to the invention used as a pulse code modulator, and, v
  • Fig. 4 shows. how the circuit according to the invention may be used as a pulse selector, a pulse generator and a pulse code demodulator.
  • the trigger comprises two pentodes l and 2 cutting off one another by crosswise direct-current feedback and having anode resistors 3, 4 respectively and a common earthed cathode resistor 5.
  • the control-grid of the pentode I is connected to a tapping point of an ohmic voltage divider comprising resistors 6, I which is connected on the one hand to the anode of the pentode 2 and on the other hand through a resistor 8, to a point of negative potential with respect to the cathodes of the tubes I. and 2.
  • the latter point is constituted by the negative terminal of a grid bias battery 9, the other terminal of which is earthed.
  • control-grid of the p l tode 2 is connected to a tapping point of a voltage divider havin resistors l0 and H, one end of which is connected to the anode of pentode I, while the other end is also connected to sistor 8. 1
  • the anodes of grid-current limiting diodes I2 and it, the cathodes of which are earthed, are connected to the respective control grids.
  • the bias from the grid bias battery '9 has a suitable value, the circuit-arrangement so.
  • the pentode I is cut off and the pentode Z'passes current
  • the latter will pass current upon va suitable increase'in potential "of the control-grid of pentod el ljand .3 will cut off the pentode 2, a subsequent decrease in potential of the control-grid of pentode l causing the trigger to resume its initial state of equilibrium.
  • the trigger circuit comprises a grid bias source 0 having a value such that, in the absence of a control-voltage, the two trigger tubes 1, 2 are operated under equal anode-current conditions.
  • the two pentodes l and 2 are cut oil in this third state of equlibrium.
  • a pulse-shaped switch-voltage us, shown diagrammatically in the drawing and applied through a capacitor l5 at the resistor 8 connected in series with the grid bias battery 53 is supplied, in series with the said cut-off grid bias, to terminals l4.
  • the control-voltage for the trigger circuit might be supplied. to the control-grid of one of the trigger pentodes, but this produces a sometimes undesirable reaction of the voltage pulses occurring in the trigger circuit on the source of controlvoltage. Therefore, as shown in Fig. 1, the control-voltage w is supplied, as is known per se, to the control-grid of a pentode 'l 0 which is connected in parallel with the pentode l and the resistor 5 included in the cathode lead thereof.
  • the output voltage of the trigger shown in Fig. 1 is taken from a tapping point ll of a voltage divider comprising resistors l8 and 19 which are connected between the anode of pentode and the negative terminal of the grid bias battery 9. The output voltage set up between the tapping of this voltage divider and earth is designated Us.
  • Fig. 1 The principal elements usedjin an experimental trigger circuit-arrangement as shown, in Fig. 1 are the following.
  • Grid bias source 9:150.volts.
  • Anode voltage 250 volts.
  • Switch-voltage about 50 volts.
  • Fig. 2 shows a number of static characteristic C'Lll'VBS holding for the circuit shown in Fig. 1. These characteristic curves show the relationship existing between the output voltage He. and the negative grid bias as set up at the junction of the grid resistors l and H at various values of the control-voltage a1 supplied to the tube 'l, as stated with the characteristic curves in question.
  • loop characteristic curves B and 'C are found at control-voltages or" 1.1 volts and l.l8 volts respectively.
  • the two trigger tubes pass current.
  • the trigger tube l is cut oil and the trigger tube 2 passes current and this state of equilibrium occurs at the last-mentioned value of U0 with a control-voltage of at least -1.18 volts, for example l.3 volts, while at a control-voltage 1n of l..1'7 volts or less, for example 0.8 volt, the characteristic curve B or a characteristic curve designated E or F is found, in which case, at a voltage uo of approximately l00 volts the tube l passes current and the tube 2 is out off.
  • the trigger circuit Upon periodical variation of the bias 'LLo between the said values (1. e., 20 v. and -l00 v. or l50 v. and l00 v.), by means of a pulseshaped switch-voltage Us, the trigger circuit appears to select in each instance, starting from the enforced third state of equilibrium, one of the two normal states of equilibrium with a'high response sensitiveness and rapidity at an instant determined by the leading edge of the switchpulse, the state of equilibrium chosen depending on a value of the applied control-voltage m above or below a critical value, the amplitude of the switch-pulses playing only a very minor part in the selection.
  • the voltage uo is thus preferably chosen to be approximately -20 volts.
  • this voltage 1L0 may, for example, be 150 volts for the position of rest of the circuit.
  • the two trigger tubes do not pass current in the third state of equilibrium.
  • the circuit again selects one of the two normal states of equilibrium in accordance with the control-voltage applied, but the response sensitiveness of the trigger is slightly lower.
  • the bias voltage bringing about the third state of equilibrium and the switch-voltage are operative across the control-grid circuits of the'trigger tubes.
  • the increased response s'ensitiveness aimed at may, as an alternative, be obtained by causing the said voltages to be operative across circuits other than the control-grid circuits, for
  • Fig. 3 shows one embodiment of a trigger circuit, used for pulsecode modulation.
  • the trigger circuit comprises a hexode 20 and a triode 2
  • is capable of cutting ofi a pentode 30 by way of a voltage divider comprising resistors 28 and 29.
  • the anode circuit of this pentode comprises an integrating network including a capacitor 3
  • a signal in, for example a speech signal, to be converted in pulse code modulation is supplied to the controlgrid circuit of a pentode 33 used as an amplifying tube and comprising'an anode resistor 34.
  • a voltage approximating the signal to be transmitted occurring across the resistor 34 is set up across the integrating network 3
  • the two anode voltages is utilised as a controlvoltage for the trigger circuit and supplied, for
  • Fig. 3 shows only those connections which are required for a clear understanding of the embodiment of invention; it is, for example, not shown how the screengrids and suppressor-grids of the tubes employed are connected to the remainder of the-circuitarrangement.
  • the fpentode 30 then passes an appreciable anode 'current, owing to which an increase in voltage set upat the integration capacitor 3
  • the trigger circuit will select such a state ofequilibrium that any difference between the compared voltages setup at the resistor 34 and the integration capacitor 3
  • the latter is substantiallyensured by the negative feedback circuit provided between the output circuit and input circuit of the trigger circuit arrangement and comprising an integrating network, and is of particular importance for various practical uses.
  • the anode circuit of the triode includes a differentiating network connected to the anode resistor 40 and comprising a capacitor 4
  • This'difierentiating network supplies a positive pulse whenever the triode 2
  • these positive pulses are transmitted to a receiver and supplied after reception, if necessary through a pulse generator to correct the shape, theamplitude and the time of occurrence, to an integrating network followed by a low-pass filter to restrict the quantization noise inherent with code modulation, the signal obtained at the output of the low-pass filter substantially corresponds to the signal to supplied to the input of the circuit shown in Fig. 3. It is pointed out that in the circuit-arrangement shown in Fig.
  • the signals to be transmitted may be converted per channel into pulse code modulation with the use of a circuit shown in Fig. 3 and then be assembled in time division.
  • the circuit-arrangement shown in Fig. .4 comprises a trigger circuit similar to Fig. 3, followed by an integrator tube, in the :anode circuit of which an integrating network is connected.
  • Fig. 4 'circuitelements similar to those of Fig. 3
  • the trigger circuit consequently operates at the same time as a pulse regeneratcr to correct the shape-the amplitude and the instant of occurrence of the incoming pulses, which may be utilised to eliminate noise in pulse code modulation receivers or in relay apparatus for pulse code modulation.
  • trigger circuit-arrangements according to the invention operate in the optimum manner, if the two trigger tubes have substantially the same steepness characteristic with respect to their crosswise coupling. It has furthermore been found that trigger circuit-arrangements of the present kind are sometimes diihcult to handle when using variable mu tubes. 1
  • a trigger-circuit arrangement comprising first and second electron discharge tubes each .havinga cathode, a grid'andan anode, means,
  • control voltage being applied to the grid of said third tubea 5.
  • a trigger-circuit arrangement as set forth in claim -l,wherein said control voltage is constituted by periodic pulses having a repetition rate whichis a harmonic of the repetition rate of said switching pulses.
  • a trigger-circuit arrangement as set forth in -claim l, wherein said means to cross-couple said tubes includes a pair of voltage dividers each connected between the anode and cathode of a respective tube, a tap on each divider being connected to the grid of the tubeassociated with the other divider.
  • a trigger-circuit arrangement as set forth in claim 1, further including a voltage divider connected between the anode of one of said tubes and through said bias voltage source to the oathode thereof, and an output circuit coupled to a tap on said divider.
  • a trigger-circuit arrangement comprising first andsecond electron discharge tubes each having a cathode, a grid and an anode, means cross-coupling said tubes whereby said arrangement exhibits two normal states of equilibrium, in one state of-which said first tube is conductive and said second tube is non-conductive, and in the other state of which the converse relationship exists, an input circuit coupled to the grid of said first tube, an output circuit coupled to the anode of said second tube, means to apply a control voltage to said input circuit to flip said arrangement from one normal equilibrium state to another, a common grid circuit coupled to the grids of said tubes and including a bias voltage source having a 'value at which both tubes are driven into equal anode current conditions representing a third state of equilibrium and a pulse generator connected in series with said source and producing rectangular switching pulses by which said trigger arrangement alternates between said third state and one of said normal states.
  • a negative feedback voltage cir- 9 1G 'cuit coupled between said output circuit and said wherein said output circuit includes a differentiinput circuit and including an integrating netating network to yield code modulation pulses.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Power Engineering (AREA)
  • Amplifiers (AREA)
  • Reduction Or Emphasis Of Bandwidth Of Signals (AREA)
  • Electrotherapy Devices (AREA)
US216487A 1950-04-28 1951-03-20 Electric circuit-arrangement Expired - Lifetime US2647208A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL291033X 1950-04-28

Publications (1)

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US2647208A true US2647208A (en) 1953-07-28

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US (1) US2647208A (de)
BE (1) BE502837A (de)
CH (1) CH291033A (de)
DE (1) DE851364C (de)
FR (1) FR1042920A (de)
GB (1) GB697127A (de)
NL (2) NL153237B (de)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838661A (en) * 1953-05-15 1958-06-10 Jeffrey C Chu Binary storage element
US2857516A (en) * 1955-10-21 1958-10-21 Burroughs Corp Electronic commutation circuit
US2979672A (en) * 1957-05-21 1961-04-11 Philips Corp Trigger circuit arrangement
US3064248A (en) * 1957-04-26 1962-11-13 Honeywell Regulator Co Digital-to-pulse train converter
US3264572A (en) * 1963-02-15 1966-08-02 Tia Electric Company Transiently regenerative amplification

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2555999A (en) * 1950-10-09 1951-06-05 Gen Electric Reset circuit for eccles-jordan triggered multivibrator circuits

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2555999A (en) * 1950-10-09 1951-06-05 Gen Electric Reset circuit for eccles-jordan triggered multivibrator circuits

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2838661A (en) * 1953-05-15 1958-06-10 Jeffrey C Chu Binary storage element
US2857516A (en) * 1955-10-21 1958-10-21 Burroughs Corp Electronic commutation circuit
US3064248A (en) * 1957-04-26 1962-11-13 Honeywell Regulator Co Digital-to-pulse train converter
US2979672A (en) * 1957-05-21 1961-04-11 Philips Corp Trigger circuit arrangement
US3264572A (en) * 1963-02-15 1966-08-02 Tia Electric Company Transiently regenerative amplification

Also Published As

Publication number Publication date
DE851364C (de) 1952-10-02
FR1042920A (fr) 1953-11-04
GB697127A (en) 1953-09-16
CH291033A (de) 1953-05-31
NL153237B (nl)
BE502837A (de)
NL91351C (de)

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