US3746939A

US3746939A - Receiver for centralized controlling apparatus

Info

Publication number: US3746939A
Application number: US00165073A
Authority: US
Inventors: K Taketa; A Miyoshi; T Kobayashi
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 1970-08-20
Filing date: 1971-07-22
Publication date: 1973-07-17
Anticipated expiration: 1990-07-17
Also published as: GB1317066A; FR2104602A5

Abstract

A receiver for a centralized controlling apparatus is used for switching a load at a given remote location upon the receipt of a transmission of a specific frequency signal from a station through a transmission or distribution line. In the receiver, a serially connected resonance coil and condenser are provided and resonated by the specific frequency signal transmitted through the transmission or distribution line. A mechanical resonator is vibrated in accordance with the resonance of the resonance coil and condenser to thereby change the magnetic flux in a magnetic circuit and to provide an induced voltage in a coil for detecting the specific frequency signal. A switching element is triggered by the induced voltage to actuate a differential relay and to thereby switch a load circuit.

Description

O i v United States Patent 1191 1 1 3,746,939 Taketa et a1. [4 July 17, 1973 1 RECEIVER FOR CENTRALIZED 3,337,805 8/1967 Joseph .1 311/147 CONTROLLING APPARATUS 3,204,513 9/1965 Balamuth 317/147 [75] Inventors: Katsuml Taketa; Alteyoshl Mlyoshi;

v nma/ y Examiner-L. T. Hlx Temmmo x-duyuhl' an of I Attorney-Norman F. Oblon, Marvin J. Spivak et a1. Fukuyama, Japan [73] Assignee: Mitsubishi Denki Knbushiki Keisha, 57 ABSTRACT Tokyo, Japan p l v A receiver for-a centralized controlling apparatus IS Filed: July 1971 used for switching a load at agiven remote location [211 App 165 073 upon the receipt of a transmission of a specific frequency signal from a station through a transmission or distribution line. In the receiver, a serially connected [30] Foreign Application Priority Data resonance coil and condenser are provided and reso- Aug. 20, 1970 Japan 45/72878 nated y the specific frequeney Signal trensmitted Aug. 21, 1970 Japan 45/73235 through the transmission or distribution line- A chanical resonator is vibrated in accordance with the ['52] U.S. Cl. 317/147, 317/148.5 B resonance of the resonance coil an nd s r t [51] Int. Cl. H0111 47/20 thereby ge t agn c flux in a magnetic circuit 581 Field of Search 317/147, 148.5 B and to provide an induced voltage in a evil for detecting the specific frequency signal. A switching element [56] Rgfgrgnm Cit d is triggered by the induced voltageto actuate a differ- UNITED STATES PATENTS ential relay and to thereby switch a load circuit.

3,213,331 10/1965 Schneider et al..' 317/147 6 Claims, 4 Drawing Figures 11] c1 Z\9 2% l5 6 IL p I 5 Patented July 17, 1973 3,746,939

2 Sheets-Sheet 1 6 IL IS F I G 2 8 6 I of z 7 INVENTORS KATaum TAKETA Meyosm mlyosm BY Tmm'omo mam mm (96 /072 5m wd m ATTORNEYS Patented July 17, 1973 2 Sheets-Sheet 2 1. Field Of The Invention This invention relates to a receiver for a centralized controlling. apparatus in which a plurality of loads, suchas electric heaters'for hot water and the like, which are located in a plurality of different remote locations canbe controlled by switching through a transmission or distribution line.

2. Description Of The Prior Art In general, it is desirable that a'centralized controlling apparatus for simultaneously controlling a pluralityof loads in different locations by switching at a substation should be operated without any errors due to the presence of noise. In addition, since a separate receiver is required at each location, the cost thereof should be as low as possible.

In the prior art and conventional centralized controlling apparatus, a signal which was different from a fun- I damental frequency and the higher harmonics thereof, such as a signal of about 3.5 times that of the fundamental frequency, was transmitted from a transmitter in a substation for a centralized controlling apparatus to a plurality of receivers. The signal so transmitted would be applied to a distribution line by multiplying the same by the fundamental frequency of the distribution line. Thus, signals of about 3.5 times that of the fundamental frequency could be effectively transmitted to electric consumers along the distribution line with very small damping, even though the signal was passed through a distribution transformer. Accordingly, it has been possible to centrally control a plurality of loads, such as electric heaters for hot water, in response to a signal transmitted at a substation, by connecting each load to one of a plurality of receivers, which would, respectively, separate the 3.5 times frequency signal from the fundamental frequency and thereby allow switching of the load by the 3.5 times frequency signal. However, while somewhat satisfactory,

, in the conventional centralized controlling apparatus,

erroneous operation would often occur in the presence of various noises on the distribution line. In addition, a relatively large size receiver was required at each load location.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to provide a new and improved economical receiver for a centralized controlling apparatus having a simple struc- I a particular frequency. A coil is provided for detecting the particular signal in accordance with an induced voltage caused by vibration of the resonator upon receipt of the desired particular frequency signal. A switching element, such as a thyristor, is actuated by the voltage induced in the coil and in turn, a differential 2. relay, such as of the thermal type, is actuated to allow power to be supplied to. a load circuit.

BRIEF DESCRIPTION OF THE DRAWINGS A more complete appreciation of this invention will be readily obtained as the same becomes better understood by reference to the following detailed description, when considered inconnection with the accompan-ying Drawings, wherein:

FIG. 1 is a block diagram of one embodiment of a receiver for use with a centralized controlling apparatus in accordance with this invention;

FIG. 2 is a partially enlarged perspective view of the receiver of FIG. 1;

FIG. 3 is a block diagram of another embodiment of a receiver in accordance with this invention; and

FIG. 4 is a partially enlarged perspective view of the receiver of FIG. 3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the Drawings, wherein like reference numerals designate identical, or corresponding parts throughout the several views, and more particularly to FIGS. 1 and 2 thereof, wherein one embodiment of a receiver in accordance with the present invention is shown as having a pair of terminals 18,28 which are connected to a source of power (not shown) at the lead-in wires at a particular remote location. A pair of load terminals 1L and 2L are connected to a load '(not shown) such, for example, as a heater for hot water or the like. A resonance condenser l is provided, and a resonance coil 2 is connected in series therewith. The serially connected resonance condenser l and resonance coil 2 are connected to the termals 1S and 28 as shown in FIG. 1. In this embodiment, the resonance condenser l and the resonance coil 2 may, for example, be set for resonating by a signal of 210 Hertz. The resonance coil 2 is wound on a central leg 31 of an iron core 3, as shown in FIG. 2. A plate type resonator 4, which may be made of a magnetic material, is provided in a predetermined gap 33 of an outer leg 32 of the iron core 3. The resonator 4 will mechanically vibrate up and down, in accordance with a change in the magnetic I flux provided to the iron core 3, when the resonance coil 2 and the condenserl are resonated. A stator 5 is fixed to one end of the resonator 4. A permanent magnet 8 is fixed to the iron core 3 at one end thereof and an iron core 7 which may be made of a magnetic material is moulded to the other end thereof. A coil 6 for detecting a signal is wound on the iron core 7. The end of resonator 4 is positioned to face the upper end of the iron core 7 with a predetermined space therebetween. A closed magnetic circuit is thus provided by the resonator 4, the outer leg 31 of the iron core 3, the permanent magnet 8 and the iron core 7. A switching element, such as a thyristor 9 is provided and a resistor 10 is provided for protecting the gate thereof. A differential relay 11 is provided and may be of the thermal responsive type. The differential relay 11 includes a bimetal 14, which is deformed by the heating of a heater 12 which is connected in series with the thyristor 9, and a switch 13 which is actuated by the deformation of bimetal 14.

It should be understood that the bimetal 14 has a dead center point so that the switch 13 will suddenly close by a deforming of the heater 12 over a specific limit and the switch 13 will suddenly open by a cooling to room temperature. One end of the heater 12 is connected to the anode of the thyristor 9. The other end of the heater 12 is connected to the terminal 28 from the power source (not shown). The coil 6 for detecting a signal is connected to the gate of the thyristor 9 through terminal a1 and the cathode of the thyristor through terminal a2. The cathode of the thyristor 9 is connected to the terminal IS-from the power source. One end of the switch 13 is connected to the terminal 28 from the power source, and the other end of the switch 13 is connected to the load terminal 2L. The load terminal IL is connected to the terminal 18 from the power source.

The operation of the receiver described above for use in a centralized controlling apparatus will now be explained. A signal (e.g., 210 Hertz) is generated at a central location, such as a substation, and then transmitted through a distribution line to the terminals 18 and 28. The resonance condenser 1 and the resonance coil 2 will be resonated by the signal received so that the resonator 4 will vibrate up and down. In the magnetic circuit which consists of the permanent magnet 8, the iron core 3, the iron core 7 and the resonator 4, a change in the magnetic flux thereof will occur by the vibration of the resonator 4, such that a small amount of induced voltage will be generated in the coil 6 for detecting the transmitted signal. The induced voltage received by the coil 6 will then be impressed on the gate of the thyristor 9 and thereby trigger the same such that the heater 12 will in turn be heated as follows. The bimetal 14 will be heated and the shape thereof will after a delay of a predetermined period deform and thereby switch the switch 13 to close the circuit. With the switch 13 closed, the terminal 28 connected to the power supply and the load terminal 2L will be connected and thereby actuate the load (e.g., a heater for hot water) which is across the load terminals 1L and 2L. Now, when transmission of the signal from the central location is discontinued, the thyristor 9 will become nonconductive so that the bimetal 14 of the heater 12 will be cooled to room temperature and the switch 13 will open such that current will no longer be applied to the load.

It should now be apparent that in accordance with the receiver of this invention, the load circuit can be closed and opened by transmitting only a small power signal from a central location, such as a substation, to a thyristor device. Accordingly, it is possible to provide an economical and compact receiver having a simple structure. In this operation, the use of a small power signal is sufficient, since the gate of a thyristor can be easily triggered with small power.

Moreover, it is noted that, in general, many noises are provided on the distribution line from the central station. However, the receiver of this invention will not operate erroneously in the presence of noise, because the differential relay used, such as of the thermal responsive type, and the load are not directly switched by the triggering of the thyristor with the noise.

Moreover, with the present invention, the mechanical resonance provided by the resonator thereof has a high sharpness response to only a specific frequency signal, such that the receiver has high reliability.

Referring now to FIGS. 3 and 4, an alternative embodiment of the receiver of the present invention is shown as including the pair of terminals 1S and 2S which are connected to a power source (not shown) through the lead-in wires at a remote location. The terminals 1L and 2L are again connected to a load, such as a heater for hot water. The resonance condenser l and the resonance coil 2 are connected in series and the series combination is further connected to the terminals 1S and 28 of the power supply, as shown in FIG.

3. Differing from the embodiment of FIGS. 1 and 2, the resonance frequency of the resonance coil 2 and the condenser l in the present embodiment are set to respond to two frequencies, such as 210 Hertz and 260 Hertz and thereby resonate by both of the signals of 210 Hertz and 260 Hertz. Here, the iron core 3 has the central leg 31 and

outer legs

32 and 34 and the resonance coil 2 is wound on the central leg 31, as shown in FIG. 4. A plate type first resonator 4 may be made of magnetic material and is positioned to face the iron core 3 with a predetermined space in the gap 33 of the outer leg 32. The first resonator 4 is mechanically vibrated up and down when the resonance coil 2 and the condenser 1 is resonated by a signal of 210 Hertz. A stator 4a is fixed to one end of the first resonator 4. A first permanent magnet 10 is fixed to the outer leg 32 at one end thereof and the other end of the magnet 10 is connected to a first core 8. A first coil 6 for detecting a received signal is wound on the first iron core 8. The edge of the first resonator 4 is positioned to face the end of the first iron core 8 with a predetermined space therebetween. A first closed magnetic circuit is formed by the first resonator 4, the outer leg 32, the first permanent magnet 10 and the first iron core 8. A plate type second resonator 5 which may be made of a magnetic material is positioned to face the iron core 3 with a predetermined space in a gap 35 of the outer leg 34. The second resonator 5 is mechanically vibrated up and down by a change in the magneticflux in the iron core 3, when the resonance coil 2 and the condenser 1 is resonated by a signal of 260 Hertz. The second resonator 5 is fixed to a stator (not shown) in a manner similar to the stator 4a, at one end thereof. A second permanent magnet 11 is fixed to the outer leg 34 at one end thereof and the other end of the magnet 11 is fixed to a second iron core 9. A second coil 7 for detecting a received signal is wound on the iron core 9. The edge of the second resonator 5 is positioned to face the end of the second iron core 9 with a predetermined gap therebetween. A second closed magnetic circuit is formed by the second resonator 5, the outer leg 34, the second permanent magnet 11 and the second iron core 9. First and second

thyristor switching elements

12 and 13 are provided.

Resistances

14 and 15 are provided for protecting the gates of the

respective thyristors

12 and 13. A differential relay 16, such as of the selfsustaining type, and being thermal responsive is provided and includes first and second heaters 17 and I8, and first and second bimetals l9 and 20 which are respectively deformed by a heating of the

heaters

17 and 18. Aswitch is activated by deforming the bimetals l9 and 20. Each of the bimetals I9 and 20, respectively, have a dead center point so that each is deformed over the dead center point by a sufficient heating of the

heaters

17 and 18. The first heater 17 is connected to the anode of the first thyristor l2 and the second heater 18 is connected to the anode of the second thyristor 13. The other ends of the first and

second heaters

17 and 18 are connected to the terminal 28 of the power source. The first and second coils 6 and 7 for 5. detecting a received signal are respectively connected to the gate and cathode terminalsal, a2, and bl, b2 of the first and second thyristors 12'and 13. The cathode of the first and

second thyristors

12 and 13 are con: nected to a terminal of the switch 190, as shown in FIG. 3. A common terminal of the switch 1901s connected to the terminal 18 of the power source.

The operation of the alternative receiver'described above for'use in a centralized controlling apparatus will now be explained. Whena signal of 210 Hertz isgenerated at a centrallocation, such as a substation, and is thereby transmitted through a distribution line to the terminals 18 and 28, the resonance condenser l and the coil 2 will be substantially resonated thereby. Ac-- cordingly, the first resonator 4 will vibrate up and down. The magnetic flux in the magnetic circuit consisting of the first permanent magnet 10, the outer leg 32 of the iron core 3, the first iron core 8, and the first resonator 4 will be changed by the vibration of the first resonator 4 whereby a small induced voltage will be provided to the first coil 6-. The induced voltage will then be impressed on'the gate of the first thyristor 12 and thereby trigger the same. Accordingly, the first heater 17 will beactuated and heated so that the first bimetal 19 will be deformed, and the switch 190 will switch as shown by the broken lines in FIG. 3. The load terminal 1L will thereby be connected to the terminal 1S of the power source. Accordingly, the load, such as a heater for hot water, will be connected to the load terminals 1L and 2L. Now, when a signal of 260 Hertz is transmitted by applying the same to the distribution line, the resonance condenser 1 and the coil 2 will again be substantially resonated whereby the second resonator will be vibrated to induce a voltage in the secondcoil 7. The second thyristor 13 will be triggered by the induced voltage and the switch 190 will switch to the position as shown by a full line in FIG. 3 such that the load will be energized by the power source.

It should now be apparent that in accordance with the second above-described embodimentof this invention, it is enough to use a small power signal, since the gate of a thyristor can easily be triggered with small power. Accordingly, with the present embodiment of this invention, it is again possible to provide an economical and compact receiver having a simple structure. Here again, no erroneous operation of the receiver in the presence of noise will occur, since a thermal responsive relay is used and therefore the load is not directly switched by triggering the thyristor with the noise. Moreover, again, the mechanical resonance provided by the resonators respectively have high sharpness and will respond only to specific frequency signals, such that the receiver has high reliability.

Obviously, numerous modifications and variations of this invention are possible in light of the above teachings. Thus, for example, while the self-sustaining type differential relay of the present invention has been described as being of the thermal response type, it should be understood that any other such differential relay could readily be used. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. A receiver for a centralized controlling apparatus comprising:

a resonance condenseranda coil which are resonated upon the receipt of a predetermined frequency signal;

an iron' core having said resonance coil wound around a leg thereof;

a resonator provided in a gap of said iron core and which is mechanically resonated by a change in the magnetic flux in said iron core when said resonance condenser and coil is resonated;

amagnetic circuit in which the magnetic flux thereof is changedby the vibration of said resonator;

a coil for detecting said predetermined frequency sig nal by an induced voltage which is provided by a change in the magnetic flux of said magnetic circuit;

a switching element which is triggered by the induced voltage in said coil; and

a difierential relay which is operated by the triggering of said switching element and which actuates a switching means in a load circuit after a predetermined period.

2. A receiver for a centralized controlling apparatus according to claim 1, wherein said differential relay comprises a heater actuated by the triggering of said switching element and a bimetal for changing said switching meansin said load circuit in accordance with the mechanical deformation thereof by heat from said heater.

3. A receiver for a centralized controlling apparatus according to claim 1, wherein said magnetic circuit comprises said resonator, a portion of said iron core, a permanent magnet fixed to said portion of said iron core, a further iron core fixed to said permanent magnet, said further iron core being wound with the coil for detecting the predetermined signal, and a gap between an edge of said further iron core and an edge of said resonator.

4. A receiver for a centralized controlling apparatus comprising:

a resonance condenser and a coil which are respectively resonated by receiving first and second signals having different frequencies;

an iron core having said resonance coil wound around a leg thereof;

a first resonator provided in a gap of said iron core at a second leg thereof, said first resonator being mechanically resonated by a change in magnetic flux in said iron core when said resonance coil and condenser is resonated by receiving said first signal;

a first magnetic circuit in which the'magnetic flux thereof is changed by vibration of said first resonator;

a first coil for detecting the first signal upon receipt of an induced voltage caused by the change of magnetic flux in the first magnetic circuit;

a first switching element which is triggered by the induced voltage received by the first coil for detecting the first signal;

a second resonator provided in a gap of a third leg of said iron core, said second resonator being mechanically resonated by a change in the magnetic flux in said iron core when said resonance coil and condenser is resonated by said second signal;

a second magnetic circuit in which the magnetic flux thereof is changed by the vibration of said second resonator;

a second coil for detecting the second signal upon receipt of an induced voltage by the change of the magnetic flux in the second magnetic circuit;

a second switching element which is triggered by the induced voltage provided in the second coil for detecting the second signal;

first and second differential relays having respective first and second delay elements which are respectively actuated by the triggering of said first and second switching elements; and,

a switching means in a load circuit which changes position in accordance with the operation of said first and second delay elements of said first and second differential relays.

5. A receiver for a centralized controlling apparatus according to claim 4, wherein said first magnetic circuit comprises the first resonator, the second leg, a first permanent magnet fixed to said second leg, a first iron core which is fixed to the first permanent magnet and upon which is wound the first coil for detecting the first signal, and a gap between an edge of the first iron core and an edge of the first resonator, and wherein said sec- 0nd magnetic circuit comprises the second resonator, the third leg, a second permanent magnet moulded in the third leg, a second iron core which is fixed to the second permanent magnet and upon which is wound the second coil for detecting the second signal, and a gap between an edge of the second iron core for the second signal and an edge of the second resonator.

A receiver for a centralized controlling apparatus according to claim 5, wherein said first and second differential relays respectively comprise a first heater actuated by the triggering of the first-switching element, a first bimetal for changing said switching means in said load circuit by mechanical deformation thereof in accordance with the heating by the first heater to provide one condition, a second heater actuated by the triggering of the second switching element, and a second bimetal for changing said switching means in said load circuit by mechanical deformation thereof in accordance with the heating by the second heater to provide another condition.

a: a: no:

Claims

1. A receiver for a centralized controlling apparatus comprising: a resonance condenser and a coil which are resonated upon the receipt of a predetermined frequency signal; an iron core having said resonance coil wound around a leg thereof; a resonator provided in a gap of said iron core and which is mechanically resonated by a change in the magnetic flux in said iron core when said resonance condenser and coil is resonated; a magnetic circuit in which the magnetic flux thereof is changed by the vibration of said resonator; a coil for detecting said predetermined frequency signal by an induced voltage which is provided by a change in the magnetic flux of said magnetic circuit; a switching element which is triggered by the induced voltage in said coil; and a differential relay which is operated by the triggering of said switching element and which actuates a switching means in a load circuit after a predetermined period.

2. A receiver for a centralized controlling apparatus according to claim 1, wherein said differential relay comprises a heater actuated by the triggering of said switching element and a bimetal for changing said switching means in said load circuIt in accordance with the mechanical deformation thereof by heat from said heater.

4. A receiver for a centralized controlling apparatus comprising: a resonance condenser and a coil which are respectively resonated by receiving first and second signals having different frequencies; an iron core having said resonance coil wound around a leg thereof; a first resonator provided in a gap of said iron core at a second leg thereof, said first resonator being mechanically resonated by a change in magnetic flux in said iron core when said resonance coil and condenser is resonated by receiving said first signal; a first magnetic circuit in which the magnetic flux thereof is changed by vibration of said first resonator; a first coil for detecting the first signal upon receipt of an induced voltage caused by the change of magnetic flux in the first magnetic circuit; a first switching element which is triggered by the induced voltage received by the first coil for detecting the first signal; a second resonator provided in a gap of a third leg of said iron core, said second resonator being mechanically resonated by a change in the magnetic flux in said iron core when said resonance coil and condenser is resonated by said second signal; a second magnetic circuit in which the magnetic flux thereof is changed by the vibration of said second resonator; a second coil for detecting the second signal upon receipt of an induced voltage by the change of the magnetic flux in the second magnetic circuit; a second switching element which is triggered by the induced voltage provided in the second coil for detecting the second signal; first and second differential relays having respective first and second delay elements which are respectively actuated by the triggering of said first and second switching elements; and, a switching means in a load circuit which changes position in accordance with the operation of said first and second delay elements of said first and second differential relays.

5. A receiver for a centralized controlling apparatus according to claim 4, wherein said first magnetic circuit comprises the first resonator, the second leg, a first permanent magnet fixed to said second leg, a first iron core which is fixed to the first permanent magnet and upon which is wound the first coil for detecting the first signal, and a gap between an edge of the first iron core and an edge of the first resonator, and wherein said second magnetic circuit comprises the second resonator, the third leg, a second permanent magnet moulded in the third leg, a second iron core which is fixed to the second permanent magnet and upon which is wound the second coil for detecting the second signal, and a gap between an edge of the second iron core for the second signal and an edge of the second resonator.

6. A receiver for a centralized controlling apparatus according to claim 5, wherein said first and second differential relays respectively comprise a first heater actuated by the triggering of the first switching element, a first bimetal for changing said switching means in said load circuit by mechanical deformation thereof in accordance with the heating by the first heater to provide one condition, a second heater actuated by the triggering of the second switching element, and a second bimetal for changing said switching means in said load circuit by mechanical deformation thereof in accordance with the heating by the second heater to provide another condition.