CA1123944A - Control system using an alternating current contactor and a direct current operated interposing relay - Google Patents
Control system using an alternating current contactor and a direct current operated interposing relayInfo
- Publication number
- CA1123944A CA1123944A CA315,293A CA315293A CA1123944A CA 1123944 A CA1123944 A CA 1123944A CA 315293 A CA315293 A CA 315293A CA 1123944 A CA1123944 A CA 1123944A
- Authority
- CA
- Canada
- Prior art keywords
- rectifier
- contactor
- control system
- control
- output terminals
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
- H01H47/007—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current with galvanic isolation between controlling and controlled circuit, e.g. transformer relay
-
- 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
- H03K17/56—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices
- H03K17/72—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region
- H03K17/725—Electronic switching or gating, i.e. not by contact-making and –breaking characterised by the components used by the use, as active elements, of semiconductor devices having more than two PN junctions; having more than three electrodes; having more than one electrode connected to the same conductivity region for ac voltages or currents
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Relay Circuits (AREA)
- Electronic Switches (AREA)
Abstract
47,617 CONTROL SYSTEM USING AN ALTERNATING CURRENT
CONTACTOR AND A DIRECT CURRENT OPERATED
INTERPOSING RELAY
ABSTRACT OF THE DISCLOSURE
An electrical control system employs a contractor having an AC operated coil, an interposing relay having DC
operated electronic switching comprising a triac and a rectifier, and a manually operated pushbutton switch. The coil is connected in series with the output of the triac and an AC power supply. The rectifier is connected to the AC supply to form a source of direct current. The push-button and the DC source are connected in series with the input of the triac whereby actuation of the pushbutton is operable to provide a low impedance path across the output terminals of the triac and activate the contactor. The contactor is mounted in a housing having a plurality of exterior cavities adapted to receive a smaller housing containing the triac,rectifier, and associated components.
The control system is particularly suited for applications wherein the pushbutton switch is situated at an extended distance from the contactor.
CONTACTOR AND A DIRECT CURRENT OPERATED
INTERPOSING RELAY
ABSTRACT OF THE DISCLOSURE
An electrical control system employs a contractor having an AC operated coil, an interposing relay having DC
operated electronic switching comprising a triac and a rectifier, and a manually operated pushbutton switch. The coil is connected in series with the output of the triac and an AC power supply. The rectifier is connected to the AC supply to form a source of direct current. The push-button and the DC source are connected in series with the input of the triac whereby actuation of the pushbutton is operable to provide a low impedance path across the output terminals of the triac and activate the contactor. The contactor is mounted in a housing having a plurality of exterior cavities adapted to receive a smaller housing containing the triac,rectifier, and associated components.
The control system is particularly suited for applications wherein the pushbutton switch is situated at an extended distance from the contactor.
Description
BACKGROUND OF THE INVENTION
Field of the Invention:
The invention relates generally to electrical apparatus and, more partlcularly, to electrical control systems employing a contactor and a manually operated push-button switch separated by an extended distance.
Description of the Prior Art:
Electricity supplies a large portion of the energy needs for commercial, industrial~and institutional users.
Many applications, including both motors and lighting, ~ .
~1~2~ 47,617 employ electrlcal energy at higher Yoltage~ or currents than can be convenlently controlled by a manu~lly operated switch. Therefore, a control system is emplo~ed wherein the m~lually operated switch electr~cally activate~ ~ contac~or to complete an electrical c~rcuit through the load, such as a~ motor or a l~ghtlng system. The contac~or generally comprises a set o~ electrical contacts Por openln~ and closin~ the circuit through the load, and a coll connec~ed in serles wlth the m~nually operated ~witch and a source o~
low voltage electr~ci~y. When the manually oper~ted switch is closed, curren~ ~lows throug~ the contactor coil to pro-duce electromagne~lc flux which acts upon the con~acts to open or close them. Additlonal protective dev~ces such as Pu~es, overload relays, and cîrcuit breakers may al80 be connected in series with the output cont~cts o~ the con tactor.
In some industrlal appl~cations, it is r~quîred that the manually operated switch be located a~ a ~on~lder-able distance :l~rom the contactor, ~or example, where a conveyor belt oper~ted by a~ electric motor is used to load material ~rom a supply dump into ~ txuck, it i~ desirable to loca~e the manually operated control switch near the truck loading statlon wh~le the conveyor motor may be loca~ed at the opposi~e end. Eowever, when an AC con~actor i~ ~ep~rated ~rom its manuall~ operated switch by more than a ~ew hundred yards~ varlous problems develop. Shunt capacltance and series impedance produced by the extended control line leads ma~ cause the contactor to fail to engage when the swltch ls operated or to re~aln en~aged when it ~s deslred ~or the contactor to drop out.
~n the past, such problems have been avolded through .~ .~, 47,617 the use of a contactor employing a direct current operated coil. However, such DC contactors are considerably more expensive than AC operated contactors of the same rating.
It is therefore desirable to provide a more economical electrical control system suitable for applications requir ing a large separation distance between the manually oper-ated switch and the contactor output.
SUM~ARY OF THE IN~ENTION ~ -In accordance with a preferred embodiment of the present invention3 there is provicled an electrical control system including a contactor having an AC operated coil~ and an interposing relay having an electronic switching device.
A manually operated control switch is connected in series with a direct current power supply and the input to the electronic switching device. The output of the electronic switching device is connected in series with the actuating coil of the contactor and an alternating current power supply. When the control switch is actuated, the electronic switching device establishes a low impedance path between the alternating current power supply and the actuating coil of the contactor, thereby energizing the coil and actuating the contactor contact.
BRIEF DESCRIPTION O~ THE DRAWINGS
~igure 1 is a schematic diagram of an interposing relay for an electrical control system having a two wire control switch circuit, Figur-e 2 is a schematic diagram of a control ~-~ system employing ~interposing relay o~ Figure 1, having a three wire control switch circuit; and Figure 3 is a perspecti~e view of the contactor 117"617 and lnterposing relay shown in Figures 2 through 4.
BRIEF ~ESCRIPTION OF THE PREFERRED EMBODIMENT
Referr~ng now to the drawings, in which corres-ponding reference characters re~er to correspondlng com-ponents, Figure 1 shows a control system 4 employing an AC
operated contactor 12 and a solid state interposing relay 30. The contactor 12 includes an alternating current operated coil 14 and a set of contacts 16 operative to .establish electrical connection between power lines 18 ::10 connected to a source of electrical power and power lines 20 oYer /0 ,7~) ~ r~connected to an electrical load through t~#~ relay J
heaters 21.- The coil 14 is connected through overloa~ relay contacts 22 to a source 24 of 120 volts alternating current.
The series combination o~ the coil 14, overload relay con~
tacts 22, and AC voltage source 24 is connected to terminals r~fJDS~ ~7 26 and 28 of ~ h~e~e~r~g relay 30 having ~C actuated electronic switching means. Also connected to the terminals 26 and 28 are the output terminals of an electronic switching device such as the triac 32. A snubbing circuit consisting of resistor R3 and a capacitor C2 is connected in parallel across the output terminals of the triac 32. The input terminal 3ll of the triac 32 is connected to a voltage div-ider consisting of resistors Rl and R2, one end of which is also connected to terminal 28. The other end of the voltage divider R1/R2 is connected to one input terminal of the full wave rectifi.er bridge devi.ce 36. The other input terminal of the rectifier bridge device 36 is connected to terminal 26 of the relay 30. The output terminals of the bridge device 36 are connected to terminals 38 and 40 of the inter-posing relay 30. A start-stop switch 42 is connected
Field of the Invention:
The invention relates generally to electrical apparatus and, more partlcularly, to electrical control systems employing a contactor and a manually operated push-button switch separated by an extended distance.
Description of the Prior Art:
Electricity supplies a large portion of the energy needs for commercial, industrial~and institutional users.
Many applications, including both motors and lighting, ~ .
~1~2~ 47,617 employ electrlcal energy at higher Yoltage~ or currents than can be convenlently controlled by a manu~lly operated switch. Therefore, a control system is emplo~ed wherein the m~lually operated switch electr~cally activate~ ~ contac~or to complete an electrical c~rcuit through the load, such as a~ motor or a l~ghtlng system. The contac~or generally comprises a set o~ electrical contacts Por openln~ and closin~ the circuit through the load, and a coll connec~ed in serles wlth the m~nually operated ~witch and a source o~
low voltage electr~ci~y. When the manually oper~ted switch is closed, curren~ ~lows throug~ the contactor coil to pro-duce electromagne~lc flux which acts upon the con~acts to open or close them. Additlonal protective dev~ces such as Pu~es, overload relays, and cîrcuit breakers may al80 be connected in series with the output cont~cts o~ the con tactor.
In some industrlal appl~cations, it is r~quîred that the manually operated switch be located a~ a ~on~lder-able distance :l~rom the contactor, ~or example, where a conveyor belt oper~ted by a~ electric motor is used to load material ~rom a supply dump into ~ txuck, it i~ desirable to loca~e the manually operated control switch near the truck loading statlon wh~le the conveyor motor may be loca~ed at the opposi~e end. Eowever, when an AC con~actor i~ ~ep~rated ~rom its manuall~ operated switch by more than a ~ew hundred yards~ varlous problems develop. Shunt capacltance and series impedance produced by the extended control line leads ma~ cause the contactor to fail to engage when the swltch ls operated or to re~aln en~aged when it ~s deslred ~or the contactor to drop out.
~n the past, such problems have been avolded through .~ .~, 47,617 the use of a contactor employing a direct current operated coil. However, such DC contactors are considerably more expensive than AC operated contactors of the same rating.
It is therefore desirable to provide a more economical electrical control system suitable for applications requir ing a large separation distance between the manually oper-ated switch and the contactor output.
SUM~ARY OF THE IN~ENTION ~ -In accordance with a preferred embodiment of the present invention3 there is provicled an electrical control system including a contactor having an AC operated coil~ and an interposing relay having an electronic switching device.
A manually operated control switch is connected in series with a direct current power supply and the input to the electronic switching device. The output of the electronic switching device is connected in series with the actuating coil of the contactor and an alternating current power supply. When the control switch is actuated, the electronic switching device establishes a low impedance path between the alternating current power supply and the actuating coil of the contactor, thereby energizing the coil and actuating the contactor contact.
BRIEF DESCRIPTION O~ THE DRAWINGS
~igure 1 is a schematic diagram of an interposing relay for an electrical control system having a two wire control switch circuit, Figur-e 2 is a schematic diagram of a control ~-~ system employing ~interposing relay o~ Figure 1, having a three wire control switch circuit; and Figure 3 is a perspecti~e view of the contactor 117"617 and lnterposing relay shown in Figures 2 through 4.
BRIEF ~ESCRIPTION OF THE PREFERRED EMBODIMENT
Referr~ng now to the drawings, in which corres-ponding reference characters re~er to correspondlng com-ponents, Figure 1 shows a control system 4 employing an AC
operated contactor 12 and a solid state interposing relay 30. The contactor 12 includes an alternating current operated coil 14 and a set of contacts 16 operative to .establish electrical connection between power lines 18 ::10 connected to a source of electrical power and power lines 20 oYer /0 ,7~) ~ r~connected to an electrical load through t~#~ relay J
heaters 21.- The coil 14 is connected through overloa~ relay contacts 22 to a source 24 of 120 volts alternating current.
The series combination o~ the coil 14, overload relay con~
tacts 22, and AC voltage source 24 is connected to terminals r~fJDS~ ~7 26 and 28 of ~ h~e~e~r~g relay 30 having ~C actuated electronic switching means. Also connected to the terminals 26 and 28 are the output terminals of an electronic switching device such as the triac 32. A snubbing circuit consisting of resistor R3 and a capacitor C2 is connected in parallel across the output terminals of the triac 32. The input terminal 3ll of the triac 32 is connected to a voltage div-ider consisting of resistors Rl and R2, one end of which is also connected to terminal 28. The other end of the voltage divider R1/R2 is connected to one input terminal of the full wave rectifi.er bridge devi.ce 36. The other input terminal of the rectifier bridge device 36 is connected to terminal 26 of the relay 30. The output terminals of the bridge device 36 are connected to terminals 38 and 40 of the inter-posing relay 30. A start-stop switch 42 is connected
2;~
47,617 through control lines 44 to the relay terminals 38 and 40.
The control lines 4LI can be of extended length of up to, for example9 several miles. A capacitor Cl ~ connected between the input terminal 34 of the triac 32 and the common term-inal 28 of the relay 30=~es~- - 5~ iS provided for noise immunity.
In operation, the START-STOP control switch 42 iS
manually actuated to the START position to establish a circuit between terminals 38 and 40 of the relay 30. ~ince - 10 the input terminals of the rectifier bridge 36 are connected -in series with the 120 volt AC source 24, manual actuation of the switch 42 to the START position is operable to establish alternating current flow between the input term-inals of the rectifier bridge 36. This current flow is sufficient to establish operating voltage upon the input terminal 34 of the triac 32, thereby triggering the triac 32 to a conductive state. A low impedance path is thus estab-lished across the terminals 26 and 28, thereby allowing sufficient alternating current flow through the coil 14 to 20 actuate the contactor 12 and close the contacts 16.
Since current flow through the control conductors 44 is DC, the undesirable ef~ects of shunt capacitance and series impedance on the conductors 44 are eliminated. Thus, the conductors 44 can be of extended length of up to several miles, instead of being limited to approximately 400 feet, as is the case for control systems employing control con-ductors havin~ AC current flowing therethrough. These benefits are obtained at much lower costs than through the prior art method of employing a contactor having a DC
ac~uated coil.
47,61~
In order to deactua~e the control system 10, the switch 42 is operated to the STOP position, thereby inter-rupting DC current flow across the output terminals of the rectifier bridge 36 and halt~ng the flow o~ current t~rough the voltage divider Rl/R2. Operating voltage is thus re-moved from the control electrode 34, causing the triac 32 to return to the non-conductive state. A high impedance path is restored across the terminals 26 and 28, thereby greatly reducing the flow of alternating current through the coil 14 and deactuating the contacts 16 of the contactor 12.
Figure 2 shows a control system 6 similar to the system Ll of Figure 1, employing a three-wire manual control circuit. All components of the system 6 to the right o~ the terminals 38 and 40 in Figure 2 are identical to corres-ponding components of the system 4 shown in Figure 1. Three control lines 44' are provided, one of which is connected between terminal 38 and one terrninal of a normally closed momentary contact pushbutton switch 48. A normally open momentary contact pushbutton switch 46 is connected between - 20 the terminal 40 and the free terminal o~ the switch 48.
Hold-in auxiliary contacts 50, operated by the coil 14, are connected across the switch 46. When the switch 46 is manually operated on a momentary basis to the closed posi-tion, a circuit is completed across the terminals 38 and 40 to actuate the coil 14 in the manner described previously.
The contacts 50 are thus operated to the closed position maintaining a closed circuit across the terminals 38 and 40 and maintaining the contactor in the actuated condition.
Manual operation o~ the switch 48 on a momentary basis to the open position is operative to deenergize the ~ 4 ~
47,617 coll 1l1 and operate all contacts of the contactor 12, in-cluding the auxiliary hold-in contacts ~0 3 to the open position. Thus, the open circuit is maintained across the terminals 38 and 40 even a~ter release of the swltch 48 to maintain the contactor 12 in the deactuated state.
Figure 3 is a perspective view of the contactor 12 and interposing relay 30 shown in Figures 1 and 2. The contactor 12 is enclosed in a molded insulatlng housing 60 having terminals 62 adapted for connection to the three line phase conductors 18 and a line neutral conductor. Terminals 64 are also provided for connect~on to an overload re:Lay 66.
The overload relay 66 includes the heater elements 21 whlch actuate bimetal elements upon overload current through the contactor to open the overload contacts 22. The overload relay 66 also includes termlnals 68 adapted for connection to the~load phase conductors 20.
The interposing relay 30 contained in a molded insulating housing 70 is mounted in a cavity in the upper right hand corner of the contactor housing 60. The housing 70 is secured to the housing 60 by any suitable method such as spring clips. The housing 70 could also be independently screw mounted upon a panel.
In each of the control systems described, a con-tactor is employed having a coil energized by alternating current. The control lines connecting the manual control switches to the relay ha~e DC current flowing therein, thereby eliminating the effects of series impedance and shunt capacitance inherent in prior art control s~stems having AC operate~ control lines. Furthermore, these desir-able effects are achieved at much lower costs than prior art ~ 47,617 control systems and employing contactors havin~ DC activatedcoils. It can be seen, therefore, that the present inven-: tion provides a control system exhibitin~ improved performance at a lower cost.
47,617 through control lines 44 to the relay terminals 38 and 40.
The control lines 4LI can be of extended length of up to, for example9 several miles. A capacitor Cl ~ connected between the input terminal 34 of the triac 32 and the common term-inal 28 of the relay 30=~es~- - 5~ iS provided for noise immunity.
In operation, the START-STOP control switch 42 iS
manually actuated to the START position to establish a circuit between terminals 38 and 40 of the relay 30. ~ince - 10 the input terminals of the rectifier bridge 36 are connected -in series with the 120 volt AC source 24, manual actuation of the switch 42 to the START position is operable to establish alternating current flow between the input term-inals of the rectifier bridge 36. This current flow is sufficient to establish operating voltage upon the input terminal 34 of the triac 32, thereby triggering the triac 32 to a conductive state. A low impedance path is thus estab-lished across the terminals 26 and 28, thereby allowing sufficient alternating current flow through the coil 14 to 20 actuate the contactor 12 and close the contacts 16.
Since current flow through the control conductors 44 is DC, the undesirable ef~ects of shunt capacitance and series impedance on the conductors 44 are eliminated. Thus, the conductors 44 can be of extended length of up to several miles, instead of being limited to approximately 400 feet, as is the case for control systems employing control con-ductors havin~ AC current flowing therethrough. These benefits are obtained at much lower costs than through the prior art method of employing a contactor having a DC
ac~uated coil.
47,61~
In order to deactua~e the control system 10, the switch 42 is operated to the STOP position, thereby inter-rupting DC current flow across the output terminals of the rectifier bridge 36 and halt~ng the flow o~ current t~rough the voltage divider Rl/R2. Operating voltage is thus re-moved from the control electrode 34, causing the triac 32 to return to the non-conductive state. A high impedance path is restored across the terminals 26 and 28, thereby greatly reducing the flow of alternating current through the coil 14 and deactuating the contacts 16 of the contactor 12.
Figure 2 shows a control system 6 similar to the system Ll of Figure 1, employing a three-wire manual control circuit. All components of the system 6 to the right o~ the terminals 38 and 40 in Figure 2 are identical to corres-ponding components of the system 4 shown in Figure 1. Three control lines 44' are provided, one of which is connected between terminal 38 and one terrninal of a normally closed momentary contact pushbutton switch 48. A normally open momentary contact pushbutton switch 46 is connected between - 20 the terminal 40 and the free terminal o~ the switch 48.
Hold-in auxiliary contacts 50, operated by the coil 14, are connected across the switch 46. When the switch 46 is manually operated on a momentary basis to the closed posi-tion, a circuit is completed across the terminals 38 and 40 to actuate the coil 14 in the manner described previously.
The contacts 50 are thus operated to the closed position maintaining a closed circuit across the terminals 38 and 40 and maintaining the contactor in the actuated condition.
Manual operation o~ the switch 48 on a momentary basis to the open position is operative to deenergize the ~ 4 ~
47,617 coll 1l1 and operate all contacts of the contactor 12, in-cluding the auxiliary hold-in contacts ~0 3 to the open position. Thus, the open circuit is maintained across the terminals 38 and 40 even a~ter release of the swltch 48 to maintain the contactor 12 in the deactuated state.
Figure 3 is a perspective view of the contactor 12 and interposing relay 30 shown in Figures 1 and 2. The contactor 12 is enclosed in a molded insulatlng housing 60 having terminals 62 adapted for connection to the three line phase conductors 18 and a line neutral conductor. Terminals 64 are also provided for connect~on to an overload re:Lay 66.
The overload relay 66 includes the heater elements 21 whlch actuate bimetal elements upon overload current through the contactor to open the overload contacts 22. The overload relay 66 also includes termlnals 68 adapted for connection to the~load phase conductors 20.
The interposing relay 30 contained in a molded insulating housing 70 is mounted in a cavity in the upper right hand corner of the contactor housing 60. The housing 70 is secured to the housing 60 by any suitable method such as spring clips. The housing 70 could also be independently screw mounted upon a panel.
In each of the control systems described, a con-tactor is employed having a coil energized by alternating current. The control lines connecting the manual control switches to the relay ha~e DC current flowing therein, thereby eliminating the effects of series impedance and shunt capacitance inherent in prior art control s~stems having AC operate~ control lines. Furthermore, these desir-able effects are achieved at much lower costs than prior art ~ 47,617 control systems and employing contactors havin~ DC activatedcoils. It can be seen, therefore, that the present inven-: tion provides a control system exhibitin~ improved performance at a lower cost.
Claims (7)
1. A control system for remote manual energization and deenergization of electrical apparatus over an extended distance, comprising:
an alternating current contactor including a coil energizable by alternating current;
an interposing relay comprising an electronic switch having an input terminal and output terminals, said output terminals connected in series circuit relationship with said coil and with an alternating current power source, a rectifier having input terminals and output terminals, means connecting said rectifier input terminals to an alternating current power source, and means connecting said electronic switch input terminal to said rectifier such that alter-nating current flow through said rectifier input terminals is operable to actuate said electronic switch and establish a low impedance across said electronic switch output terminals, control conductors connected to said rectifier output terminals; and control switch means remote from said interposing relay and said contactor, and connected to said control conductors such that operation of said control switch means to a closed position is operable to establish direct current flow through said control conductors and said control switch means when and only when said control switch means are in the closed position and alternating current flow through said rectifier input terminals when and only when said control switch means are in a closed position, whereby said electronic switch is actuated and a low impedance 47,617 path is established across said electronic switch output terminals to energize said contactor coil when and only when said control switch means are in the closed position
an alternating current contactor including a coil energizable by alternating current;
an interposing relay comprising an electronic switch having an input terminal and output terminals, said output terminals connected in series circuit relationship with said coil and with an alternating current power source, a rectifier having input terminals and output terminals, means connecting said rectifier input terminals to an alternating current power source, and means connecting said electronic switch input terminal to said rectifier such that alter-nating current flow through said rectifier input terminals is operable to actuate said electronic switch and establish a low impedance across said electronic switch output terminals, control conductors connected to said rectifier output terminals; and control switch means remote from said interposing relay and said contactor, and connected to said control conductors such that operation of said control switch means to a closed position is operable to establish direct current flow through said control conductors and said control switch means when and only when said control switch means are in the closed position and alternating current flow through said rectifier input terminals when and only when said control switch means are in a closed position, whereby said electronic switch is actuated and a low impedance 47,617 path is established across said electronic switch output terminals to energize said contactor coil when and only when said control switch means are in the closed position
2. A control system as recited in claim 1 wherein said rectifier input terminals are connected to said electronic switching device output terminals and said rectifier output terminals are connected to said control conductors, whereby operating power for said control system is entirely obtained from a single associated AC power source.
3. A control system as recited in claim 2 wherein said electronic switching device comprises a triac having two output terminals and a gate terminal and said control system comprises a voltage divider connected between one of said rectifier input terminals and one of said triac output terminals, said triac gate terminal being connected to said voltage divider at an intermediate point thereof, whereby current flow into said rectifier is operable to trigger said triac and establish a low impedance path through said triac output terminals to energize said contactor.
4. A control system as recited in claim 3 wherein said control conductors, said rectifier output terminals, and said control switch means are connected in series circuit relationship.
5. A control system as recited in claim 4 wherein said control conductors have a length of 400 feet or more.
6. A control system as recited in claim 1 wherein said interposing relay comprises a housing enclosing said electronic switching device and said rectifier, and said housing is mounted upon said contactor.
47,617
47,617
7. A control system as recited in claim 1 wherein said contactor includes a housing, said interposing relay is mounted upon said housing and comprises an enclosure within which are mounted said electronic switch and said rectifier, and said control switch means are located at an extended distance from said contactor and interposing relay.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US87187878A | 1978-01-24 | 1978-01-24 | |
| US871,878 | 1978-01-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1123944A true CA1123944A (en) | 1982-05-18 |
Family
ID=25358363
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA315,293A Expired CA1123944A (en) | 1978-01-24 | 1978-10-31 | Control system using an alternating current contactor and a direct current operated interposing relay |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS54113239A (en) |
| BE (1) | BE873685A (en) |
| CA (1) | CA1123944A (en) |
| ES (1) | ES240915Y (en) |
| GB (1) | GB2013426B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE33504E (en) * | 1983-10-13 | 1990-12-25 | Lutron Electronics Co., Inc. | Wall box dimer switch with plural remote control switches |
| US4563592A (en) * | 1983-10-13 | 1986-01-07 | Lutron Electronics Co. Inc. | Wall box dimmer switch with plural remote control switches |
-
1978
- 1978-10-31 CA CA315,293A patent/CA1123944A/en not_active Expired
-
1979
- 1979-01-10 GB GB7900865A patent/GB2013426B/en not_active Expired
- 1979-01-23 ES ES1979240915U patent/ES240915Y/en not_active Expired
- 1979-01-23 JP JP565179A patent/JPS54113239A/en active Pending
- 1979-01-24 BE BE0/193061A patent/BE873685A/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| JPS54113239A (en) | 1979-09-04 |
| ES240915Y (en) | 1981-04-16 |
| ES240915U (en) | 1980-11-16 |
| BE873685A (en) | 1979-07-24 |
| GB2013426A (en) | 1979-08-08 |
| GB2013426B (en) | 1982-09-02 |
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