US2752511A - Electrical timing circuits - Google Patents

Electrical timing circuits Download PDF

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Publication number
US2752511A
US2752511A US235625A US23562551A US2752511A US 2752511 A US2752511 A US 2752511A US 235625 A US235625 A US 235625A US 23562551 A US23562551 A US 23562551A US 2752511 A US2752511 A US 2752511A
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US
United States
Prior art keywords
valve
relay
contacts
circuit
grid
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
US235625A
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English (en)
Inventor
Beaufoy Raymond
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British Telecommunications PLC
British Telecommunications Research Ltd
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British Telecommunications PLC
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Publication date
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Publication of US2752511A publication Critical patent/US2752511A/en
Anticipated expiration legal-status Critical
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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
    • H03K17/28—Modifications for introducing a time delay before switching
    • H03K17/288—Modifications for introducing a time delay before switching in tube switches
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/07—Controlling traffic signals
    • G08G1/085—Controlling traffic signals using a free-running cyclic timer

Definitions

  • the present invention relates to electrical timing circuits and is particularly concerned with improved arrangements for producing an operation at the end of a timed period which period is preferably capable of variation.
  • the operation concerned comprises the release of an electric relay at a desired time after the performance of a switching operation.
  • the timed period may be adjusted by a manually-operated control associated with the timer and the timer is also susceptible to external control which may take two forms.
  • One of these controls serves to inhibit the timing operation so that the period from which timing commences may be determined by the removal of this control, while the second produces a re-setting action which may be either partial or complete, that is to say when the second control becomes operative the operation which has taken place is wiped out to a greater or less extent and as soon as the control is removed timing commences from the point to which the circuit has been set back.
  • a timing device having these characteristics may be useful for a number of purposes but it finds particular application to the control of traffic signals.
  • the first control mentioned above may be effective as long as a trafiic lane is denied right of way so that timing only commences when right of way is granted, while the second control may be effective due to the passage of vehicles over a detector in a traific lane possessing right of Way whereby the timer is reset so that the right of way period is extended by further trafiic arriving.
  • the timer according to the invention also possesses the advantages that it is small in size, involving only two thermionic valves, which may be located in the same envelope, and it is constant in its timing regardless of external conditions such as temperature, variation of supply voltage and the adjustment of the relay.
  • a relay arranged to effect a switching operation at the end of the timed period is connected in the anode circuit of a thermionic valve the potential on the control grid of which is adapted to be varied under the control of a second thermionic valve on which the external control contacts operate and the operation of which is also controlled by contacts of the relay.
  • the relay will of course have additional contacts controlling the operation for which the timing is required.
  • the two valves may be interconnected so as to form a multi-vibrator of substantially known type when the external controls are not operative.
  • the timing is controlled by means of a capacitor the state of charge of which is varied by the different controls.
  • the valve which is not directly associated with the relay is arranged to operate as an oscillator valve the output from which when applied to the grid of the other valve serves to render it negative so that the valve no longer conducts and the relay in its anode circuit is therefore released.
  • V2 is coupled to the grid of V1 by way of capacitor C3, resistor R7, capacitor C1 and resistor R2. Consequently a trigger action takes place which serves to cut off V2 and repeat the cycle. Accordingly, if S1 remains open and S2 closed, the circuit will continue to operate in a manner similar to a multi-vibrator with a main period, i. e. the time during which V1 is cut-off, determined by the values of R1 and C1. The period during which V2 is cut off need only be sufiiciently long to ensure the proper performance of the switching operations effected by relay RA.
  • capacitor C1 remains connected to the SO-volt supply after the relay is operated.
  • This continuous application of SO-volts by way of resistor R8 to the grid of V2 serves to balance out the drop in voltage by way of resistor R6 and rectifier MRA and accordingly the potential of the grid of V2 remains substantially constant and the relay is therefore held operated. In other words, the timer has been reset and when contacts S1 are again opened, will start to time its full period.
  • valve V1 If contacts S2 remain open, it is impossible for valve V1 to conduct since its anode is disconnected and consequently no change in the potential of the grid of V2 occurs and the timer remains inoperative.
  • Capacitor C10 is charged by the flow of grid current by way of resistor R12, trimmer R13 and resistor R14, while at the same time SO-volts positive is applied over the normally closed relay contacts RBI and rectifier MRB in its high resistance direction to the grid of valve V4 which accordingly conducts after a short period.
  • relay RE is operated and opens contacts RBI so that the grid of V3 becomes negative with respect to its cathode by an amount represented by SO-volts less the trimmer volts.
  • Capacitor C10 now starts to discharge through resistor R10 and this proceeds until a point is reached at which the valve starts to conduct.
  • resistor R11 enables a partial resetting operation to take place if the contacts S1 are only closed for a very short interval.
  • the tuned circuit includes the primary or the secondary of the transformer TR.
  • the contacts S2 may be arranged to short-circuit either winding but it may be more convenient from other points of view to operate on the secondary so that one of the contacts may be earthed. It may also be desirable to shunt the rectifier MRB by a high value resistor to give operation which is more consistent and less dependent on the characteristics of the rectifier.
  • a resettable electrical'timin'g circuit for effecting a switching operation at the end of a predetermined period comprising in combination a first thermionic valve, a relay in the anode circuit of said valve, first contact operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, a capacitor connected to the grid of said second valve, means for charging said capacitor, means controlled by said second contacts of said relay for progressively discharging said capacitor and thereby causing said second valve to conduct, connections between the anode of said second valve and the grid of said first valve whereby when said second valve conducts said first valve is cut oil and external control contacts for resetting said timing circuit by cancelling a partial operation thereof.
  • a resettable electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay and comprising a rake-break combination for controlling the timing circuit, a second thermionic valve, a capacitor connected to the grid of said second valve, a circuit including the break contacts of said second relay contacts for charging said capacitor, a circuit including the make contacts of said second relay contacts for progressively discharging said capacitor and thereby causing said second valve to conduct, connections between the anode of said second valve and the grid of said first valve whereby when said second valve conducts said first valve is cut oft" and external control contacts shunting said break contacts of said second relay contacts for resetting said timing circuit by canceilin a partial operation thereof.
  • a resettable electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, a capacitor connected to the grid of said second valve, means for charging said capacitor, means controlled by said second relay contacts for progressively discharging said capacitor and thereby causing said second valve to conduct, connections between the anode of said second valve and the grid of said first valve whereby when said second valve conducts said first valve is cut off, first external control contacts cooperating with said second contacts of said relay for resetting said timing circuit by cancelling a partial operation thereof and second external control contacts located in the anode circuit or" said second valve for inhibiting the timing operation of said timing circuit- 5.
  • a resettable electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, a capacitor connected to the grid of said second valve, means for charging said capacitor, means controlled by said second contacts of said relay for progressively discharging said capacitor and thereby causing said second valve to conduct, coupling means between the anode and grid circuits of said second valve whereby when said valve conducts oscillations are set up, a connection between the anode of said second valve and the grid of said first valve whereby when said second valve is set in oscillation said first valve is cut ofif, and external control contacts for resetting said timing circuit by cancelling a partial operation thereof.
  • the anode circuit of said second valve includes a parallel tuned circuit comprising a capacitor and a transformer by means of which feed-back is provided to the grid circuit.
  • An electrical timing circuit for eifecting a switching operation at the end of a predetermined period comprising in combination, a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, means for varying the potential of the grid of said first thermionic valve under the control of said second thermionic valve, circuit connections including said second relay contacts for initiating a progressive change in the grid potential of said second valve and means for causing said change to become very rapid after it has proceeded to a predetermined extent thereby securing a rapid change of said second valve to the opposite state and hence a rapid control of said first valve.
  • An electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination, a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, means for reducing the potential of the grid of said first thermionic valve under the control of said second thermionic valve, circuit connections including said second relay contacts for initiating a progressive increase in the grid potential of said second valve and means for causing said increase to become very rapid after it has proceeded to a predetermined extent thereby securing a rapid change of said second valve to the conducting state and hence a rapid cut-ofl of said first valve.
  • An electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination, a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, means for reducing the potential of the grid of said first thermionic valve under the control of said second thermionic valve, circuit connections including said second relay contacts for initiating a progressive increase in the grid potential of said second valve and circuit connections between the anode of said first valve and the grid of said second valve such as to cause said increase to become very rapid after it has proceeded to a predetermined extent thereby securing a rapid change of said second valve to the conducting state and hence a rapid cut-oi'i of said first valve.
  • An electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination, a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, circuit connections including said second relay contacts for initiating a progressive increase in the grid potential of said second valve and thereby causing said second valve to conduct, coupling means between the anode and grid circuits of said second valve whereby when said valve starts to conduct oscillations of rapidly increasing amplitude are set up, and circuit connections including a rectifier between the grid of said second valve and the grid of said first valve whereby when said second valve is set in oscillation a negative potential for effecting the cut-off of said first valve is rapidly built up on the grid thereof.
  • An electrical timing circuit for effecting a switching operation at the end of a predetermined period comprising in combination, a first thermionic valve, a relay in the anode circuit of said valve, first contacts operated by said relay for controlling an external circuit, second contacts operated by said relay for controlling the timing circuit, a second thermionic valve, a capacitor connected to the grid of said second valve, means for charging said capacitor, means controlled by said second relay contacts for progressively discharging said capacitor so as to increase the grid potential and thereby cause said second valve to conduct, coupling means between the anode and grid circuits of said second valve whereby when said valve starts to conduct oscillations of rapidly increasing amplitude are set up, and circuit connections including a rectifier between the grid of said second valve and the grid of said first valve whereby when said second valve is set in oscillation a negative potential for effecting the cutofi of said first valve is rapidly built up on the grid thereof.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Magnetically Actuated Valves (AREA)
  • Electronic Switches (AREA)
US235625A 1950-07-31 1951-07-07 Electrical timing circuits Expired - Lifetime US2752511A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB19094/50A GB690503A (en) 1950-07-31 1950-07-31 Improvements in or relating to electrical timing circuits employing thermionic valves

Publications (1)

Publication Number Publication Date
US2752511A true US2752511A (en) 1956-06-26

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Family Applications (1)

Application Number Title Priority Date Filing Date
US235625A Expired - Lifetime US2752511A (en) 1950-07-31 1951-07-07 Electrical timing circuits

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US (1) US2752511A (fr)
FR (1) FR1040158A (fr)
GB (1) GB690503A (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2939083A (en) * 1958-06-23 1960-05-31 John D Hague Double integration memory circuit responding to bi-polar pulse video input signal
US2952800A (en) * 1957-11-07 1960-09-13 Howard D Gulnac Time delay device
US3056051A (en) * 1960-11-25 1962-09-25 Robert L Burdick Multipurpose electronic timer
DE1149388B (de) * 1960-09-27 1963-05-30 Vakutronik Veb Elektronischer Zeitschalter
US3100351A (en) * 1960-03-07 1963-08-13 Burroughs Corp Keyboard training device
DE1171011B (de) * 1959-04-14 1964-05-27 Western Electric Co Schaltungsanordnung zur Erzeugung einer Ausgangsspannung, die nach einer bestimmten Zeitspanne auf einen Schaltvorgang folgt
US3233190A (en) * 1963-01-03 1966-02-01 Bell Telephone Labor Inc Astable multivibrators with progressively varying time constants
US3378693A (en) * 1964-07-25 1968-04-16 Schmidt Metallwarenfabrik Fa G Impulse sender for the drive of timing devices, preferably automatic permanent calendars

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE949413C (de) * 1954-02-04 1956-09-20 Licentia Gmbh Zeitkreis
DE1272188B (de) * 1964-07-15 1968-07-04 Signalbau Huber Muenchen K G Signalschalter fuer einen Lichtsignalgeber

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2458283A (en) * 1944-10-23 1949-01-04 Automatic Elect Lab Impulse generator
US2583792A (en) * 1948-05-22 1952-01-29 Lloyd E Nelson Timer circuit
US2591810A (en) * 1948-09-25 1952-04-08 Rca Corp Electrical time-delay network

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2458283A (en) * 1944-10-23 1949-01-04 Automatic Elect Lab Impulse generator
US2583792A (en) * 1948-05-22 1952-01-29 Lloyd E Nelson Timer circuit
US2591810A (en) * 1948-09-25 1952-04-08 Rca Corp Electrical time-delay network

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2952800A (en) * 1957-11-07 1960-09-13 Howard D Gulnac Time delay device
US2939083A (en) * 1958-06-23 1960-05-31 John D Hague Double integration memory circuit responding to bi-polar pulse video input signal
DE1171011B (de) * 1959-04-14 1964-05-27 Western Electric Co Schaltungsanordnung zur Erzeugung einer Ausgangsspannung, die nach einer bestimmten Zeitspanne auf einen Schaltvorgang folgt
US3100351A (en) * 1960-03-07 1963-08-13 Burroughs Corp Keyboard training device
DE1149388B (de) * 1960-09-27 1963-05-30 Vakutronik Veb Elektronischer Zeitschalter
US3056051A (en) * 1960-11-25 1962-09-25 Robert L Burdick Multipurpose electronic timer
US3233190A (en) * 1963-01-03 1966-02-01 Bell Telephone Labor Inc Astable multivibrators with progressively varying time constants
US3378693A (en) * 1964-07-25 1968-04-16 Schmidt Metallwarenfabrik Fa G Impulse sender for the drive of timing devices, preferably automatic permanent calendars

Also Published As

Publication number Publication date
GB690503A (en) 1953-04-22
FR1040158A (fr) 1953-10-13

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