US3846641A - Control system for a plurality of loads - Google Patents

Control system for a plurality of loads Download PDF

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Publication number
US3846641A
US3846641A US39612573A US3846641A US 3846641 A US3846641 A US 3846641A US 39612573 A US39612573 A US 39612573A US 3846641 A US3846641 A US 3846641A
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United States
Prior art keywords
supply conductors
loads
control system
load
voltage
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Expired - Lifetime
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English (en)
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Y Eguchi
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Hochiki Corp
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Hochiki Corp
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    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/07—Programme control other than numerical control, i.e. in sequence controllers or logic controllers where the programme is defined in the fixed connection of electrical elements, e.g. potentiometers, counters, transistors
    • 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
    • H03K17/292—Modifications for introducing a time delay before switching in thyristor, unijunction transistor or programmable unijunction transistor switches

Definitions

  • ABSTRACT In a control system wherein a plurality of loads are sequentially connected in parallel across supply conductors, each load is connected across the supply conductors through a switching circuit which is closed a predetermined interval after the application of an operating voltage, the loads in the second and succeeding stages are connected across the supply conductors through transfer switches which are operated in response to the operation of the loads in the preceding stages, a relay contact is connected in parallel with each transfer switch, and relay means is provided for each stage for opening the contact when the load and the switching circuit in that stage are energized, and
  • the supply conductors are terminated with an impedance element, and a test voltage lower than the operating voltage is connected to the supply conductors at the time of the conduction test.
  • This invention relates to a control system, and more particularly to a control system for sequentially operating a plurality of loads connected in parallel to a source of supply, for example, fire-preventing doors or shutters, unlocking means for emergency doors, smoke exhaust fans, automatic water sprinklers, alarms, etc., installed in buildings.
  • a source of supply for example, fire-preventing doors or shutters, unlocking means for emergency doors, smoke exhaust fans, automatic water sprinklers, alarms, etc.
  • the loads are connected to the supply conductors through respective switch circuits which are closed a predetermined interval after the application of an operating voltage under the control of suitable time delay means, such as timers.
  • Loads in the second and succeeding stages are connected to the supply conductors through transfer switches which are operated when the loads in the preceding stages are operated.
  • Relay contacts are closed when the operating voltage is impressed upon the loads and the switching circuits in respectively preceding stages, and are opened a predetermined interval thereafter.
  • the relay contacts are connected in parallel with the transfer switches, and an impedance is connected across the ends of the supply conductors.
  • a first source to supply the operating voltage
  • a second source for supplying a test voltage which is lower than the operating voltage
  • switch means for selectively connecting the supply conductors to either one of the first and the second sources
  • a meter for measuring the current flowing through the supply conductors and the terminal impedance when the second source is connected to the supply conductors.
  • FIG. 1 is a connection diagram of a prior-art control system for sequentially operating a plurality of loads, for example door unlocking circuits;
  • FIG. 2 shows a sectional view of a door unlocking device utilized in the circuit shown in FIG. 1;
  • FIG. 3 shows a connection diagram of the novel control system embodying the present invention.
  • FIG. 4 shows voltage and current waveforms of the various elements utilized in the circuit shown in FIG. 3.
  • FIG. 1 of the accompanying drawing illustrates a typical connection diagram of a prior-art control system in which the loads are shown as a plurality of door unlocking devices DL DL connected in parallel across supply conductors CL and L.
  • Each of the door unlocking device comprises an operating coil L for unlocking a door, not shown, a time delay circuit T which are connected in parallel across supply conductors CL and L, a relay A including a contact a and connected in parallel with the time delay circuit T, and a transfer switch MS connected in parallel with contact a.
  • the operating coil L comprises the coil of an electromagnet for operating a door unlocking device. More particularly, in the example shown in FIG. 2, a fire preventing door DR is provided with an armature PT secured thereto, and a permanent magnet M. The magnetic flux produced by the permanent magnet M flows through a magnetic circuit including a yoke for the permanent magnet M and the electromagnet and the armature as shown by solid line arrows X whereby the armature PT is attracted by the magnet assembly to lock the door in the closed position.
  • the transfer switch MS when the transfer switch MS is operated in this manner, that is transferred from the upper contact to the lower contact, the door unlocking circuit DL, is deenergized and the next door unlocking circuit DL is energized. In this manner, a plurality of door unlocking circuits are energized sequentially.
  • relay A is actuated after a predetermined time determined by the delay circuit T associated therewith thereby closing a contact a in parallel with the transfer switch MS of the second door unlocking circuit DL For this reason, even if the transfer switch M of the preceding door unlocking circuit DL were not operated due to a fault or the like cause, the second door would be positively unlocked after a predetermined interval.
  • control system described above is advantageous in that a plurality of loads or door unlocking circuits are operated sequentially and that succeeding door unlocking circuits are caused to operate sequentially even when a preceding door unlocking circuit fails to operate, since the door unlocking circuits are opened prior to their operation, it is impossible to test their conduction.
  • door unlocking circuits DL, and DL are shown as the loads it should be understood that various emergency apparatus of the type described above are used in practical applications.
  • a switching circuit SC is connected in series with each door unlocking circuit.
  • the switching circuit SC comprises a silicon controlled'rectifier SR connected in series ,with the coil L, a control transistor Tr, for the silicon controlled transistor, resistors R,, R, and R capacitors C, and C,, a diode D, and a Zener diode ZD which are connected as shown.
  • a protective circuit PC is connected in series with said serially connected'coil L and switching circuit SC.
  • the protective circuit PC comprises a relay A, a control transistor Tr, connected in series therewith, resistors R R and R,,, a capacitor C and Zener diodes ZD, and ZD, which are con'nectedas shown.
  • a plurality of door unlocking circuits DL,, DL,...., each having a construction as above described, are connected in parallel across supply conductors CL and L.
  • Each of the second and succeeding door unlocking circuits DL,, DL,,... is connected to the supply conductors CL and L through the transfer switch MS shown in FIG. 1 or other suitable switch which is switched when the preceding load is operated, and the contact a of the relay A of the preceding load.
  • the ends of the supply conductors are terminated by a terminal impedance element RL such as a resistor ora Zener diode.
  • the charging of capacitor C is commenced and after a predetermined interval t, determined by the time constant C,R,, the terminal voltage across capacitor C, reaches a predetermined value thereby rendering conductive Zener diode ZD, and hence silicon controlled rectifier SR.
  • Capacitor C functions as a bypass capacitor to maintain a sufficiently large gate voltage enough to render ON the silicon controlled rectifier even when the voltage of source E, fluctuates.
  • coil L is energized, thus unlocking the door shown in FIG. 2.
  • transfer switch MS When the door is opened, transfer switch MS will be thrown to the lower contact thereby deenergizing the circuit DL, in the first stage and energizing the door unlocking circuit DL,,. In this manner, the loads or the door unlocking circuits are operated sequentially.
  • the capacitor C is included in the control circuit for transistor Tr, of the protective circuit PC, after a predetermined interval t, determined by a time constant C,R,, the control current is decreased to turn OFF transistor Tr, thus deenergizing r'elay A. As a result, contact a is reclosed. Under normal condition, since the transfer switch MS is operated prior to the elapse of interval t the reclosure of contact a does not cause any action, but when the transfer switch MS fails to transfer, the reclosure of contact a causes sequential operation of the succeeding door unlocking circuits DL,, DL,,...
  • switch SW of source device S is thrown to the lower contact to impress voltage V, of source E, across supply conductors CL and L. Since voltage V, is lower than the operating voltage V, Zener diodes ZD,, ZD, and ZD, are not turned ON. Accordingly, the switching circuit SC is in its OFF condition to isolate coil L from supply conductors CL and L. Thus, the protective circuit PC is also in the inoperative condition whichis important.
  • the invention provides a new and improved control system capable of effecting not only sequential operation of a plurality of loads such as emergency machines and apparatus but also the conduction test of supply conductors for the loads.
  • a control system for sequentially operating a plurality of loads connected in parallel across supply conductors, said control system comprising a plurality of switching circuits for respective loads, each one of said switching circuits being closed a predetermined interval after the application of the operating voltage for connecting the associated load to said supply conductors, a plurality of transfer switches for connecting the loads to said supply conductors in the second and succeeding stages, means responsive to the operation of the load in the preceding stage for operating the transfer switch of the succeeding stage to connect the load of said succeeding stage across said supply conductors, a plurality of relay contacts respectively connected in parallel with said transfer switches, relay means connected in preceding stages for opening said contacts when the loads and said switching circuits in the pre- S ceding stages are energized, and for closing said contacts after a predetermined interval, and a terminal impedance element connected across the end terminals of said supply conductors.
  • control system which further comprises a first source for supplying a normal operating voltage for said loads, a second source having a test voltage lower than said normal operating voltage, a transfer switch for selectively connecting said supply conductors across either one of said first and second said sources, and a meter for measuring the current flowing through said supply conductors when said second source is connected thereto.
  • each one of said respective switching circuits comprises a silicon controlled rectifier connected in series with one load, a Zener diode connected to supply a gate voltage to said silicon controlled rectifier, a CR time constant circuit for applying a driving voltage for said Zener diode a predetermined interval after energization of the switching circuit, said Zener diode not becoming conductive when supplied with said test voltaga r a delay time of said switching circuit, said Zener diode becoming not conductive when applied with said test voltage which is lower than said operating voltage, and said last-named CR time constant circuit having a time constant which is predetermined such that said control current for said transistor is maintained for a interval somewhat longer than the operating time of said load ai1d is' tlien decreased toEi valuFsufficient to interrupt said transistor.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Electronic Switches (AREA)
  • Relay Circuits (AREA)
  • Power-Operated Mechanisms For Wings (AREA)
  • Respiratory Apparatuses And Protective Means (AREA)
US39612573 1972-09-22 1973-09-10 Control system for a plurality of loads Expired - Lifetime US3846641A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9569972A JPS5127826B2 (US07345094-20080318-C00003.png) 1972-09-22 1972-09-22

Publications (1)

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US3846641A true US3846641A (en) 1974-11-05

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US39612573 Expired - Lifetime US3846641A (en) 1972-09-22 1973-09-10 Control system for a plurality of loads

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US (1) US3846641A (US07345094-20080318-C00003.png)
JP (1) JPS5127826B2 (US07345094-20080318-C00003.png)
CH (1) CH577222A5 (US07345094-20080318-C00003.png)
DE (1) DE2347714A1 (US07345094-20080318-C00003.png)
FR (1) FR2200658B1 (US07345094-20080318-C00003.png)
GB (1) GB1400679A (US07345094-20080318-C00003.png)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3937978A (en) * 1975-05-30 1976-02-10 Owenby Jr Carl L Remote control systems for electrically operated loads
US3979648A (en) * 1975-03-10 1976-09-07 Nohmi Bosai Kogyo Co., Ltd. System for operating fire prevention devices
FR2358903A1 (fr) * 1976-07-23 1978-02-17 Nohmi Bosai Kogyo Co Ltd Systeme de protection contre l'incendie
US5469000A (en) * 1989-08-15 1995-11-21 Geysen; Hendrik M. Switching device with a plurality of switches responsive to an input signal level
US5521359A (en) * 1995-04-18 1996-05-28 Bone; Charles A. System for coordinating operation of microwave oven with a second appliance
CN113629987A (zh) * 2021-08-03 2021-11-09 深圳市康佳壹视界商业显示有限公司 Led屏电气控制系统

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5460678A (en) * 1977-10-22 1979-05-16 Shinmei Kougiyou Kk Controller among process

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3566147A (en) * 1967-02-21 1971-02-23 Atlas Copco Ab Control device for variable sequential connection and disconnection of plant components

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3566147A (en) * 1967-02-21 1971-02-23 Atlas Copco Ab Control device for variable sequential connection and disconnection of plant components

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3979648A (en) * 1975-03-10 1976-09-07 Nohmi Bosai Kogyo Co., Ltd. System for operating fire prevention devices
US3937978A (en) * 1975-05-30 1976-02-10 Owenby Jr Carl L Remote control systems for electrically operated loads
FR2358903A1 (fr) * 1976-07-23 1978-02-17 Nohmi Bosai Kogyo Co Ltd Systeme de protection contre l'incendie
US5469000A (en) * 1989-08-15 1995-11-21 Geysen; Hendrik M. Switching device with a plurality of switches responsive to an input signal level
US5521359A (en) * 1995-04-18 1996-05-28 Bone; Charles A. System for coordinating operation of microwave oven with a second appliance
CN113629987A (zh) * 2021-08-03 2021-11-09 深圳市康佳壹视界商业显示有限公司 Led屏电气控制系统

Also Published As

Publication number Publication date
GB1400679A (en) 1975-07-23
FR2200658B1 (US07345094-20080318-C00003.png) 1979-05-04
DE2347714A1 (de) 1974-05-02
FR2200658A1 (US07345094-20080318-C00003.png) 1974-04-19
JPS4951479A (US07345094-20080318-C00003.png) 1974-05-18
JPS5127826B2 (US07345094-20080318-C00003.png) 1976-08-14
CH577222A5 (US07345094-20080318-C00003.png) 1976-06-30

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