EP0112740A1 - Electronic control circuit for a multi-mode apparatus comprising a mechanism with an electromagnet - Google Patents

Abstract

The invention relates to an electronic device controlling the electromagnet of a multiple operation electrical apparatus. The electromagnetic coil (14) is connected in series to a triac (25) regulated by a generator (32) associated with a monostable flip-flop (34) designed to supply a single pulse of time-length T at each order from a logic circuit (36). A selector (38) cooperates with each output S1, S2, S3 . . . of the logic circuit (36) to choose a predetermined mode of operation of the apparatus (10), particularly remote-operated switch, contactor, or ON-OFF mode.

Description

The invention relates to a device for controlling an electrical appliance equipped with a motor electromagnet mechanism causing a change in state of the movable contact at each excitation pulse from the electromagnet coil, said device comprising a circuit for supplying the electromagnet and a control member inserted in said supply circuit to ensure or interrupt the excitation of the coil.

A known device of the kind mentioned (see French patent No. 2,482,773) consists of a bistable electromechanical remote control switch whose change of state causes the opening or closing of mechanical contacts at each supply of the coil of the electro- actuation magnet. mechanism. The supply of the coil is generally of short duration, for example the duration of pressing of a push button constituting the control member. The volume occupied by the electromagnet inside the modular box of the remote control switch is large compared to the other elements of the mechanism. When the coil is energized by means of an AC voltage source, the closing and opening of the contact of the remote control switch takes place at any time of the sinusoid. Any possibility of synchronous engagement therefore remains impossible.

The object of the invention is to remedy these drawbacks and to allow the production of a modular device with multiple reliable operation, the space-saving electromagnet of which is suitable for synchronous engagement.

The control device according to the invention is characterized in that said control member comprises a controlled static switch whose conduction is controlled by an electronic control circuit capable of de delivering control pulses for a predetermined duration T, the ignition of the switch being inhibited outside the time interval T, so as to limit the flow of current through the coil of the electromagnet.

The static controlled switch is advantageously constituted by a triac electrically connected in series with the coil of the electromagnet supplied by an alternating voltage source. The electronic circuit comprises a monostable flip-flop whose output cooperates with a synchronous pulse generator circuit for striking the static switch in the vicinity of the zero crossing of the voltage U and whose input is connected to a logic circuit of command, said flip-flop supplying the generator circuit with a single pulse of duration T at each order from the logic circuit.

The use of the triac associated with its control circuit makes it possible to obtain operating reliability linked to the calibration of the control pulse for priming the triac, and to the availability of a high motive power by supercharging the the electromagnet for a very short time. The volume of the electromagnet is reduced and also allows synchronous engagement which consists in supplying the coil at the start of an alternation of the voltage U.

The logic circuit comprises a plurality of outputs delivering output signals S ₁ , S ₂ , S ₃ ... distinct according to the state of the input signals E ₁ , E ₂ , E ₃ ... determined by means of control K. These include one or more auxiliary contacts actuated manually or automatically by a PLC or a programmer, and a position detector of the mobile contact of the device.

A selector is advantageously associated with the control circuit for taking into account a predetermined output signal Si, S ₂ , S ₃ of the logic circuit corresponding to a particular operating mode of the device, namely by remote control, contactor or open - close. The operating mode is indicated to the user by means of a signaling device cooperating with the selector.

• - la figure 1 montre le schéma synoptique d'un appareil électrique à électro-aimant commandé par impulsions de courte durée au moyen du circuit électronique selon l'invention;
• - la figure 2a représente un mode de réalisation d'un appareil modulaire et du circuit électronique associé logés dans deux boîtiers juxtaposés;
• - la figure 2b est une variante de la fig. 2a, à boîtier commun intégrant l'appareil et le circuit électronique;
• - la figure 3 illustre le circuit logique du module de commande selon la fig. 1;
• - la figure 4 représente pour les trois positions du sélecteur la forme des signaux de commande en différents points du circuit de la fig. 3.

Other advantages and characteristics will stand out, more clearly from the description which follows of different embodiments of the invention, given by way of nonlimiting examples and represented in the appended drawings, in which:

• - Figure 1 shows the block diagram of an electrical device with electromagnet controlled by short duration pulses by means of the electronic circuit according to the invention;
• - Figure 2a shows an embodiment of a modular device and the associated electronic circuit housed in two juxtaposed boxes;
• - Figure 2b is a variant of FIG. 2a, with a common housing integrating the apparatus and the electronic circuit;
• - Figure 3 illustrates the logic circuit of the control module according to fig. 1;
• - Figure 4 shows for the three positions of the selector the shape of the control signals at different points in the circuit of FIG. 3.

In Figures 1 and 2a is shown a pole of a modular electrical device 10 whose actuation mechanism of the movable contact 12 comprises an electromagnet 14 controlled by an electronic control circuit 16. The electrical device 10 is constituted, for example, by a remote control switch, the mechanism of which causes the state of the movable contact 12 to change at each excitation pulse from the coil of the electromagnet 14. This remote control switch could be replaced by any other low-voltage bistable switchgear, in particular a circuit breaker with remote control for closing and opening.

The device 10 is housed in a molded housing 18 placed side by side with the module 20 of the electronic circuit 16. The device 10 comprises a first pair of terminals 22a, 22b for connecting the use circuit in connection with the movable contact 12, and a second pair of terminals 24a, 24b for connection of the electromagnet 14 to the electronic circuit 16 of the control unit 20. The electromagnet 14 of the mechanism for actuating the movable contact 12 is arranged inside the box 18, but it is clear that it could be placed in an intermediate box between the box 18 and the module 20 when the device 10 is a saying _- Remote trunk.

The electromagnet 14 is connected in series with a controlled static switch, in particular a triac 25, intended to open or close the supply circuit 26 of the electromagnet 14, connected to an alternating voltage source U by power conductors P and N associated with terminals 27a, 27b of the module 20. The triac 25 is incorporated in the module 20 which is electrically connected to the electromagnet 14.by connection conductors 28a, 28b connected respectively to the terminals 24a, 24b of the apparatus 10. The supply circuit 26 of the apparatus 10 comprises in series the conductor N, the terminal 27b of the module 20, the triac 25, the connecting conductor 28b, the terminal 24b, the coil of the electromagnet 14, the terminal 24a, the connecting conductor 28a, the terminal 27a and the conductor P. The voltage source U is formed by way of example by the 220 Volt alternating network. A resistor R _A is interposed between terminal 27a and a power supply 30 constituted by a voltage regulator circuit which supplies the DC supply voltage to the electronic circuit 16 from the AC voltage U of the network.

The triac 25 control electrode is connected to a generator circuit 32 capable of delivering synchronous pulses at each half-period of the voltage U and in the vicinity of zero voltage for priming the triac 25. At the generator circuit 32 is associated with a monostable flip-flop 34, the output of which provides a single pulse for each order applied to the input from a logic control circuit 36. The width T of the output pulse of the flip-flop 34 determines the time during which the generator circuit 32 will supply ignition pulses to the triac 25, that is to say the time of current flow in the electro- magnet 14 of the device 10. The monostable rocker 34 is formed by a Schmitt trigger or by any other operator or shaping circuit whose change of state from 0 to 1 of the input brings the output to the state 1, the output remaining in this state for a duration T defined by the characteristics of the operator, regardless of the time during which the input remains in state 1.

A selector 38 with three adjustment pads is electrically interposed between the logic control circuit 36 and the monostable rocker 34 to choose one of the outputs of the logic circuit 36 corresponding to a predetermined operating mode of the device 10. The first position CT (output S1) requires contactor operation, the second position TL (output 5 ₂ ) corresponds to the operating mode as a remote control switch, and the third ON-OFF (output S ₃ ) to open and close operation depending on the position contacts 12 of the device. The switching of the selector 38 takes place from the front face of the module 20, and the three distinct operating modes depend on the shape of the control signals of the logic circuit 36 cooperating in combination with a detector 40 of the position of the contacts 12 of the remote control switch 10 and control means K constituted by one or more auxiliary contacts actuated by pushbuttons, a programmer or an automaton. The auxiliary contacts of the control means K of the logic circuit 36 are electrically connected by a circuit of link 42 to terminals 44a, 44b of module 20.

The detector 40 for the position of the contacts 12 of the device 10 comprises, for example, a Reed relay, the control contact 46 of which is actuated by a permanent magnet 48 movable secured to a member 50 for transmitting the movement of the main movable contact 12 of the device 10. The control contact 46 of the detector 40 is either open when the movable contact 12 of the device 10 is itself open, or closed in the closed position of the contact 12.

FIG. 2b represents a one-piece device 100 integrating the electronic circuit 16 and electromagnet remote control 14 assembly. The selector 38 is associated with a signaling device (not shown), for example with light-emitting diodes, which indicates on the front face the operating mode of the device 10 (fig. 2a) or 100 (fig. 2b) depending on the position of the selector 38.

FIG. 3 shows the diagram of the logic circuit 36 for controlling the monostable rocker 34. The control means K (fig. 1 and 2a) comprise a first push button BP ₁ used to generate a common control signal E ₁ corresponding to the contactor, remote control and ON closing function. A second push button BP _{2 is} used to deliver a control signal E ₂ capable of ensuring the OFF opening function. The two control signals E ₁ , E ₂ each have two logic states 0 or 1 corresponding respectively to the opening and closing of the push buttons BP1, BP ₂ . A third control signal E ₃ comes from the position detector 40 such that the opening or closing of the main movable contact 12 of the associated device 10 results respectively in a logic state 0 or 1 at the output of the detector 40. The positive logic is thus used to explain the operation of circuit 36.

The logic circuit 36 comprises a first sub-assembly SE provided with a NAND logic gate 60 which supplies a signal output S ₁ applied via a diode D ₁ to the first pad CT of the selector 38. To one of the inputs of door 60 is connected the output of a NAND door 62 of which one of the inputs is connected at the output of detector 40, and the other input of which is connected by a NON 64 gate to the output of push button BP ₁ . The other input of the door 60 is connected to another NAND door 66 connected on the one hand to the push button BP ₁ and on the other hand to the detector 40 via a door NO 68. It is noted that the door NAND 62 logic is sensitive to input signals E ₁ and E ₃ , while the two inputs of gate 66 receive control signals E ₁ and E ₃ . This first sub-assembly SE ₁ generates the contactor function, and the output voltage S ₁ of the NAND gate 60 is defined by the following relation:

The truth table below represents the logical states of the signals at different points of the SE ₁ subset (contactor logic):

In this table, logic state 0 represents an absence of information or voltage, while logic state 1 identifies with the presence of voltage information (positive logic). Note that the output voltage S ₁ is equal to 1 for the combination E ₁ .E3 or E ₁ . E ₃ , and zero for the combination E ₁ .E ₃ or E ₁ . E ₃ . So that the signal output S ₁ of the sub-assembly SE ₁ goes to logic state 1 corresponding to an order to change the position of contact 12 of the device 10, it is necessary that the input signals E ₁ and E ₃ have a state different logic from each other. The output signal S ₁ remains at state 0 when the inputs of SE ₁ simultaneously receive control signals E ₁ and E ₃ having the same logic state.

The second stud TL of the selector 38 is connected via a diode D ₂ directly to the first push button BP ₁ . The output voltage S ₂ applied to the terminal TL initializes the remote control function generated exclusively by the actuation of the push button BP ₁ . Each closing of BP ₁ corresponds to a logic state 1 of S ₂ capable of causing a change of state of the contact 12 of the device 10 independently of the positions of the detector 40 and of the second push button BP ₂ .

dans laquelle les tensions de commande E₁,E₂ et E₃ appliquées aux entrées de SE₂ correspondent respectivement à l'état du premier bouton poussoir BP₁, du deuxième bouton poussoir BP₂ et du détecteur 40 de position à relais Reed. La table de vérité à logique positive montre les états logiques des signaux en différents points du sous-ensemble SE₂ :

The third ON-OFF pad of the selector 38 is connected by a diode D ₃ to a NAND gate 70 of a second sub-assembly SE ₂ of the circuit 36. One of the inputs of the gate 70 is connected to the output of a NAND gate 72 connected in parallel to the input terminals of gate 66; the door 72 being sensitive to the control signals E ₁ and E3. The other input of door 70 is controlled by another NAND door 74 connected to the detector 40 and to the second push button BP ₂ to receive the control signals E ₂ and E ₃ . This second subset SE ₂ with three input variables provides the opening - closing function, and the output voltage S ₃ of the gate 70 is determined by the following logical relation:

in which the control voltages E ₁ , E ₂ and E ₃ applied to the inputs of SE ₂ correspond respectively to the state of the first push button BP ₁ , of the second push button BP ₂ and of the position detector 40 with Reed relay. Positive logic truth table shows states signal logic at different points in the SE ₂ subset:

The transition to logic state 1 of the output voltage S ₃ occurs for the combination E ₂ .E ₃ or E ₁ . E ₃ , that is to say when the control voltages E ₂ and E ₃ are in state 1 corresponding to the simultaneous closing of the push button BP ₂ and of the contact 12 of the device 10, or when the voltage E ₁ is in state 1 (closing of BP ₁ ) while the control voltage E ₃ is at the same time in state 0 (opening of contact 12).

It is noted that the two sub-assemblies SE ₁ and SE ₂ of the logic circuit 36 are produced by means of NAND and NON gates, but it is obvious that the circuit 36 could be designed with other combinational operators making it possible to obtain the functions logic (1) and (2) corresponding to the output voltages S ₁ and S ₃ .

The push button BP ₁ , the push button BP ₂ and the detector 40 are respectively connected to one of the poles of the power supply 30 by resistors R ₁ , R ₂ , R ₃ and to the other pole by resistors R ₆ , R ₄ and R ₅ in series with a diode D ₅ .

The operation of the apparatus 10 associated with the electronic circuit 16 is as follows, FIG. 4 illustrating the shape of the signals at different points of the circuit 16 according to the position of the selector 38:

1) TELERUPTEUR MODE

The selector 38 is in the TL position while the other two positions CT and ON-OFF are out of service. The apparatus 10 behaves like a remote control switch. The output S ₂ of the logic circuit 36 is connected to the input of the monostable flip-flop 34. Each time the first push-button BP ₁ is closed, there is a control command at the output S ₂ (logic state 1). The flip-flop 34 supplies a single pulse of constant duration T to the generator circuit 32 at each order of the output S ₂ . The pulses delivered by the generator circuit 32 for priming the triac 25 appear synchronously at each half-period and in the vicinity of the voltage zero during the duration T of the control pulse of the monostable rocker 34. It results therefrom synchronous engagement. The passage time of the current in the coil 14 of the remote control switch is very limited, even if the push button BP ₁ remains pressed in the closed position. The calibration of the control pulse by the rocker 34 makes it possible to have a high motive power by supercharging the coil 14 of the remote control switch for a very short time fixed by T. It is noted that the measurement of the position of the movable contact 12 n 'does not intervene in this operating mode.

2) CONTACTOR MODE

The selector 38 is switched to the CT position, the other two positions TL and ON-OFF being out of service. The order of control at the output of door 60 of the first SE ₁ sub-assembly depends on the state of the main movable contact 12 (detector 40) and on the first push button BP ₁ , as formulated in relation (1) former. The transition to the logic state 1 of the output voltage S ₁ corresponding to a command to change the position of the contact 12, requires that the push button BP ₁ and the detector 40 are at different logic levels from one another, that is to say that the contact 12 is open when BP ₁ is closed, or that the contact 12 is closed when the push button BP _{1 is released} which automatically returns to the open position. In the first case, holding the BP button ₁ in the closed position ensures the contact 12 of the device 10 closes (see column 2, fig. 4). In the second case, the release of the BP button ₁ causes the contact 12 to return to the open position (see column 4, fig. 4). The device 10 thus behaves as a contactor. Note that pressing the push button BP ₁ in the closed position of the contact 12 does not cause any change in the state of the device 10 (column 3). The same is true when the button BP _{1 is released} and the contact 12 is open (column 5). In the latter two cases, the contact 12 remains in its initial position.

The state change order (columns 2 and 4) issued by the output S ₁ of the circuit 36 to the monostable flip-flop 34 causes the triac 25 to start and the coil 14 to be supplied, which remains energized for the duration T fixed by lever 34.

3) OPENING - CLOSING MODE

The selector 38 is switched to the ON-OFF position, the other two positions CT and TL being out of service. The order of control at the output of door 70 of the second sub-assembly SE ₂ depends on the state of the main movable contact 12 (detector 40), the first push button BP ₁ and the second push button BP ₂ , such as formulated in relation (2) above. The transition to logic state 1 of the output voltage S ₃ takes place when the main contact 12 is closed and the push button BP ₂ is actuated (column 8, fig. 4), or when the contact 12 is open and the BP button ₁ is closed (column 9, Fig. 4). This results in the excitation of the coil 14 during the time T determined by the flip-flop 34, so as to cause in the first case the opening of the contact 12, and in the second case its closing. The other sequences are indicated on the truth table.

It is noted that at each position CT, TL and ON-OFF of the selector 38 corresponds a predetermined operating mode of the device 10, namely contactor, remote control switch and open-close. This mode is indicated by the LED signaling device. It is also possible to combine two pads of the selector 38 to obtain a particular sequence, for example by switching the selector both to the TL position and to the ON-OFF position. By pressing the first push button BP, the device behaves as a remote control switch. The closing of the second push button or auxiliary contact BP ₂ causes the final opening of the contact 12 of the device 10.

A timer safety device (not shown) is arranged at the output of the monostable lever 34 to prevent several successive attempts to initiate the triac 25 due to repetitive operations of the push buttons BP ₁ and BP ₂ . A protective member, in particular a fuse or a thermistor (not shown) is connected in series with the coil of the electromagnet 14, the latter being thus protected in the event of possible destruction of the triac 25.

The invention is of course by no means limited to the mode of implementation more particularly described and shown in the accompanying drawings, but it extends quite the contrary to any variant remaining within the framework of electrotechnical equivalences.

Claims (10)

1. Control device for an electrical appliance equipped with a motor electromagnet mechanism causing a change in state of the movable contact at each excitation pulse of the electromagnet coil, said device comprising a circuit for supplying the electromagnet and a control member inserted in said supply circuit to ensure or interrupt the excitation of the coil, characterized in that said control member comprises a controlled static switch (25), the conduction is controlled by an electronic control circuit (16) capable of delivering control pulses for a predetermined duration T, the ignition of the switch (25) being inhibited outside the time interval T, so to limit the passage of current in the coil of the electromagnet (14). 2. Control device according to claim 1, characterized in that the supply circuit of the electromagnet (14) is formed by an alternating voltage source U, and that the static switch (25) comprises at minus a thyristor or a triac electrically connected in series with the coil of the electromagnet (14). 3. Control device according to claim 1 or 2, characterized in that the electronic circuit (16) comprises a monostable rocker (34) whose output cooperates with a generator circuit (32) of synchronous pulses for the ignition of the static switch (25) in the vicinity of the zero crossing of the voltage U, and the input of which is connected to a logic control circuit (36), said flip-flop (34) providing the generator circuit (32) with a single pulse of duration T at each order from the logic circuit (36). 4. Control device according to claim 3, characterized in that the logic circuit (36) comprises a plurality of outputs delivering output signals S ₁ , S ₂ , S ₃ ... distinct according to the state of the input signals E ₁ , ^E ₂ , E ₃ ... determined by control means K, and qu 'A selector (38) is interposed between the logic circuit (36) and the monostable rocker (34) to choose the operating mode of the device (10), the number of adjustment pads CT, TL, ON-OFF. .. of the selector (38) being identical to the number of outputs of the logic circuit (36). 5. Control device according to claim 4, characterized in that the control means K comprise one or more auxiliary contacts actuated manually or automatically by an automaton or a programmer, and a detector (40) of contact position (12) mobile device (10). 6. Control device according to claim 5, characterized in that the control means K of the logic circuit (36) are provided with a first push button BP ₁ used to generate a common input signal E ₁ corresponding to the contactor, remote control and closing ON function, and a second push button BP ₂ used to deliver an input signal E ₂ for the opening command OFF, the third input signal E ₃ coming from the detector (40 ) of position secured to a member for transmitting (50) the movement of the movable contact (12). 7. Control device according to claim 6, characterized in that the logic circuit (36) comprises a first subset SE ₁ of combinational operators sensitive to the two input signals E ₁ and E ₃ , and arranged to deliver at the first pad CT of the selector (38) an output signal S ₁ defined by the relation E ₁ .E ₃ + E ₁ . E3 corresponding to the contactor logic. 8. Control device according to claim 6 or 7, characterized in that the logic circuit (36) com carries a second subset SE ₂ of combinatorial operators with three input variables E ₁ , E ₂ , E ₃ , and intended to supply the third ON-OFF pad of the selector (38), an output signal S ₃ defined by the relation E ₂ .E ₃ ^{+ E} ₁ . ^E 3 corresponding to the opening - closing logic. 9. Control device according to claim 6, 7 or 8, characterized in that the second stud TL of the selector (38) cooperates directly with the first push button 8P ₁ , each actuation of which causes the emission of a command order at the output S ₂ of the circuit (36) corresponding to the remote control function. 10. Control device according to one of claims 3 to 9, characterized in that the generator circuit (32) for controlling the triac (25) supplies synchronized calibrated pulses at each half-period and in the vicinity of the zero crossing. of the alternating voltage U during the time interval T of the command pulse delivered by the monostable flip-flop (34), that a timer safety device is arranged in the electronic circuit (16) to prevent successive attempts d priming of the triac (25) at too short time intervals, and that a protective member, in particular a fuse circuit breaker or a thermistor. is connected in series with the triac (25) and the solenoid coil (14).

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