FR2719172A1 - Circuit device for the generation of operating voltages for input and / or output modules of automation devices. - Google Patents

Abstract

Circuit device for generating operating voltages for modules of input and / or output elements of automation devices which are connected in particular to a central module, characterized in that between the poles of a DC voltage source is connected in series an inverter (4) with an ohmic or capacitive decoupled output, a constant current source (5) and a voltage regulator (6) generating by stabilization a DC voltage which is lower than the voltage from the DC voltage source.

Description

The invention relates to a circuit device for generating

  operating voltages for input and / or output modules of automation devices which are connected

  in particular to a central module.

  Input and output modules for automation devices

  Programmable memory devices are connected, via lines, to external devices and units, such as limit switches, contactors, relays, magnetic valves etc. located in a technical installation. The input and output modules capture signals from units which are part of a process and deliver control signals to units of that process which is controlled, regulated and / or controlled by

  the respective automation device with programmable memory.

  The input and output modules are strongly decentralized.

  and are connected, via an interface, to other devices

  automation reils, for example to a module or a uni-

  central tee which includes at least one processor, memory or other components necessary or suitable for controlling

or regulating the process.

  A direct current converter is known which comprises a direct current converter into connected alternating current,

  output side, via a filter circuit comprising

  laying reactors and capacitors, to a circuit

  cooked rectifier. In this DC converter, there is no transformer for ohmic separation (JP 2-123 967 (A) in Patents Abstracts of Japan, Sect. E, 1990, Vol. 14 N '354 (E-958 )). In a known frequency changer circuit, the voltage of the network frequency is rectified and is converted into a high frequency alternating voltage which is supplied, by capacitors, to a second rectifier circuit to which a converter is connected.

  direct voltage to alternating voltage (EP O 398 722 A2).

  A known DC voltage regulator includes a source

  constant current and a transistor which is mounted in parallel

  related to a load and which regulates the output voltage

(US, 3,524,124).

  There is also known a serial DC voltage regulator further comprising a parallel regulator (Electronics,

  August 2, 1973, Vol. 46, Book 16, p 91 to 94).

  In the input and output modules, there are

  electronic components such as memories for input and output signals, and logic circuits

  for controlling memories and transmission procedures

  between the respective input and output modules and

  other modules, such as central units. These components

  sants require operating voltages. Here comes the invention which aims to improve, for the input and / or output modules, a circuit as simple as possible for the generation of at least two operating voltages of which at least one is stabilized and the other has separate potential.

  The object of the invention is achieved by a circulating device

  cooked of the type mentioned in the introduction, in accordance with the invention

  tion, by the fact that between the poles of a DC voltage source are mounted an inverter with decoupled output and a voltage regulator generating a voltage lower than the voltage of the DC voltage source. Preferably, are

  connected in series, between the poles of a voltage source

  continuous, an inverter with an ohmically decoupled output, a

  constant current source and a general voltage regulator

  rant, by parallel stabilization, a continuous tension which

  is less than the voltage of the DC voltage source.

  The current of the constant current source determines, for the logic circuits and the components of the transmission interfaces of the respective input and / or output modules, the maximum available current which is the basis of the power

  supplied by the inverter and the voltage regulator. The availability

  sitive in series implies a lower charge current for the DC voltage source. This is particularly important because of the lower power dissipation which results in a reduction in the heating of the modules. By

  the inverter, the output of which is ohmically decoupled, a voltage

  Separate potential is available in the input modules

  inlet and outlet and is particularly suitable for

  supply to the bus coupling points.

  The object of the invention is also achieved by a circuit device of the type described in the introduction by the fact that between the poles of a DC voltage source are mounted in parallel an inverter with a capacitively decoupled output and a regulator. of tension which generates a tension

  which is less than the voltage of the continuous voltage source

  naked. The inverter, the output of which is capacitively decoupled

  and whose output voltage is set, has only a very low

  ble power dissipation and provides an ohmically separated voltage which is particularly suitable for the circuits of a transfer interface. The other voltage regulator can also act as an inverter to generate a rate

  high availability for low power dissipation

  sance. Low power dissipations lower the temperatures in the input and / or output modules which, most of the time, are not cooled by forced ventilation. In another preferred embodiment, provision is made for the rectifier to include a bridge circuit with non-contact circuit elements and for the bridge diagonal

  is connected by capacitors to the inputs of a rectifier

  bridge bridge, entries which are mounted after the smoothing element. With this device having its own inventive character, it is generated, from a direct current, a continuous voltage ohmically decoupled by means of capacitors, therefore without transformer component. By avoiding the intervention of a transformer, the space requirement of the circuit is reduced. Of

  moreover, circuit manufacturing is particularly economical.

  that and the high availability rate.

  It is appropriate that the smoothing elements are connected to the operating voltage connections of transmitting and / or receiving elements for a transmission channel. This transmission channel ensures the exchange of information with other modules, for example, the central unit. For this channel of

  transmission, it may be a bus and in particular of prefec-

of a serial bus.

  In particular, the constant current source includes the undu-

  their connected in series with a resistor and the voltage at the resistor is applied, as an effective value of the adjusted quantity, to a voltage to frequency converter which is connected, on the output side, to a circuit for generating two rectangular voltages out of phase with 180 'which are applied

  each to a pair of transistors of the on-bridge circuit

  odor. This device generates a constant current flowing through the resistor, various voltage drops occurring, depending on the height of the input voltage, at the level

  of the inverter with the rectifier placed after it.

  It is particularly advantageous that the DC output voltage to the smoothing elements is applied, as an effective value of the quantity adjusted to a voltage to frequency converter whose frequency modifies the duration of

  switching on the contactless circuit elements of the

  their in the direction of a reduction in adjustment deviation.

  The circuit frequency of the contactless circuit elements is intended, in this embodiment, to regulate the DC output voltage. Changing the frequency

  of circuit is manifested in a modification of the resistance

  this blind capacitors supplied by the elements of

  circuit i.e. the voltage drop, occurring at the con-

  densifiers, varies with circuit frequency. Thus, the regulation of the DC output voltage is carried out with

  simple means. This type of regulation has in particular

  link to a high availability rate.

  The voltage regulator with the stable parallel branching

  In particular, the generator generates the operating voltage for the memories and other components, for example for the control of transmission and storage in the input and output modules. Since their current consumption does not

  varies very little in the different functional states-

  power dissipation occurring in the organ

  parallel stabilizer, is relatively weak.

  Various other features of the invention emerge

  moreover from the detailed description which follows.

  One embodiment of the object of the invention is shown

  shown, by way of nonlimiting example, in the accompanying drawings.

  Fig. 1 is a block diagram of a circuit device for generating operating voltages for modules

  input and / or output of automation devices.

  Fig. 2 is a diagram of an inverter forming part of the circuit device according to FIG. 1 including rectifier

is placed after.

  Fig. 3 is a diagram of a constant current circuit forming part of the circuit device according to FIG. 1

  with a voltage regulator mounted in series.

  Fig. 4 is a diagram of another embodiment

  of an inverter with an applied input current.

  Fig. 5 is a diagram of an inverter whose direct output voltage is regulated and the input voltage does not

is not.

  An input and output module 1 shown diagrammatically

  in fig. 1, for example of a programmed memory command-

  table, is connected by lines 2, 3 to the outputs of a device

  network supplying an unregulated direct output voltage

  for example, 24 V. The network device not shown generates, for example from the network voltage of 220 or 110 V, a direct voltage using a transformer.

  preceding a bridge rectifier respectively full wave.

  Lines 10, 11 are for example part of a bus connecting the input and / or output modules to each other and with a

  central module which is also not shown.

  At the outputs of the network device is connected, via lines 2, 3, the series device of an inverter 4, a constant current source 5 and a voltage regulator 6 which generates, by parallel stabilization , a continuous tension

  Release. Inverter 4 generates an alternating circuit voltage

  cooked ohmically separated from the circuit by lines 2, 3, which is then converted into a DC voltage. The inverter 4 forms part of the load resistance of the constant current regulator 5. The constant current flows from the

  constant current regulator 5, in the voltage regulator

  Sion 6 which generates, for example, a regulated voltage of 5 V. The inverter 4 generates, by means of a rectifier to which we will return in more detail later, a continuous output voltage for example of 5 V. data processing circuits are mounted in the input and output module 1. These are, for example, memories for the input and output signals of one or more processors which control the output and the input of

  data on a bus and circuits that control the trans-

  data missions to a bus. In fig. 1, there are shown the circuits necessary for the transmission of data to a bus, therefore transmitter and receiver components, which are

  designated as a whole by 7.

  The receiver and transmitter components 7 are connected, by their operating voltage inputs, to outputs 8, 9 of the

  rectifier placed after the inverter 4.

  Lines 10, 11 of a transmission channel are connected to the outputs respectively to the inputs of the receiver and transmitter components 7, this transmission channel being constituted by

especially by a serial bus.

  The voltage regulator 6 delivers, at the outputs 12, 13, the regulated DC voltage. At outputs 12, 13 are connected

  data processing circuits which carry the reference

  ce 14 in fig. 1. The data processing circuits 14 include the memories, possibly a processor or another control element for the memories and are supplied with operating voltages by the voltage regulator 6. The circuits 14 are connected, for example by the intermediate of terminals 15 of module 1, external lines 16 leading to units of a technical unit. These units are, for example, limit switches, initiators, relays, contactors, magnetic valves, etc. used to

  the command respectively to the regulation of a process.

  Between the circuits 14 and the transceiver elements 7,

  signals are separated ohmically for example by the inter-

  medium of an optocoupler. The transceiver elements

  7 are, for example, part of an RS 485 interface.

  The inverter 4, shown in detail in FIG. 2, comprises four contactless circuit elements 17, 18, 19, arranged in a bridge. Contactless circuit elements 17

  to 20 are bipolar transistors, the circuit elements

  cooked 17, 18 being npn transistors and the circuit elements 19, 20 pnp transistors. Circuit elements

  17 to 20 will be designated in the following by transistors.

  The transistors 17, 19 are connected in series in the first half of the bridge and the transistors 18, 20 are connected in series

  in the second half of the bridge. The collectors of transis-

  tors 17, 18 are connected to line 2. The transmitters of the trans

  sistors 17, 18 are respectively connected to the emitters of the transistors 19, 20. The collectors of the transistors 19, 20

  are connected to the constant current source 5.

  The switching on and off times of the transistors 17 to 20 are controlled by an oscillator 21 which delivers two

  180-phase pulse repeats, one of which applies

  applies to the base areas of transistors 17, 18 and the other

  to the base areas of the transistors 18, 20.

  A first capacitor 22 provided with an electrode is connected to the emitters of the transistors 17, 18. The other electrode of the

  capacitor 22 is connected to one of the inputs 23 of a circuit

  cooked in rectifier bridge 24. A second capacitor 25 is placed between the emitters of the transistors 18, 19 and the other

  input 26 of the rectifier bridge circuit 24. A condensa-

  smoothing tor 29 is mounted parallel to the outputs 27, 28 of the rectifier bridge circuit 24 respectively of the full wave rectifier. The outputs 27, 28 respectively precede a suppressor reactance coil 30, 31. The connections of the suppressor reactance coils 30, 31, diverted from the rectifier bridge circuit 24, are connected to a diode

  Zener 32 which is also connected to outputs 8, 9. The separation

  ohmic tion between the transistors 17 to 20 and the rectifier bridge circuit 24 is caused by the capacitors 22, 25. A transmission transformer is no longer necessary

for ohmic separation.

  The rectifier 4 constitutes, with the rectifier bridge circuit

  sor 24, a separate ohmic direct current converter-

  without transformer. Due to the elimination of the trans-

  formatter, the size of the DC converter is considerably reduced. The components of the converter

  direct current can therefore be arranged with the components

  circuit elements 7 and circuits 14 on a common printed circuit board. In addition, the manufacture of the DC converter is more advantageous because

  capacitors are less expensive than transformers.

  According to fig. 3, the collectors of the transistors 19, 20 are connected to the Drain electrode of a field effect transistor 33 which is the member for adjusting the constant current source 5. The source electrode of the field effect transistor

  33 is connected, by a resistor 34, to the connection of cou-

  voltage regulator service rant 6.

  A connection is connected to the service current connection.

  connection of operating voltage 35 of an operational amplifier

  nel, the other operating voltage connection of which is not mentioned, is connected to line 3. The output 12 is also connected to the operating current connection of the voltage regulator.

  6. An input of the operational amplifier 36 is connected

  dedicated to a common connection of two resistors 37, 38 for-

  mant a voltage divider and connected in series between the elect

  source trode of the field effect transistor 33 and line 3. The output of the operational amplifier 36 precedes the emitter of a transistor 39 whose collector is connected to the control electrode of the field effect transistor 33 and

  to a resistor 40 which is also applied to line 2.

  The base area of transistor 39 is always connected to a

  output line 12. Resistors 34, 37, 38, the amplifier

  operational cator 36, transistor 39, resistor 40 and transistor 33 are part of the constant current source 5.

  The second input of the operational amplifier 36 is placed

  created at a reference voltage source called block 42 and

  delivering a constant reference voltage while monitoring

its own operating voltage.

  The service current connection of the voltage regulator 6 is also connected to the voltage output 12 to which

  connected a voltage divider consisting of two resistors

  tances 43, 44 connected in series and connected to line 3. The common connection point of the resistors 43, 44 is connected to an input of another operational amplifier 45, the other input of which undergoes the reference voltage which is supplied by block 42. The operational amplifier 45 is supplied with operating voltage by the operating voltage connection and line 3. The output of the operational amplifier is connected to the base area of a bipolar transistor 46

  whose collector is connected to output 12 and its emitter

  it is connected to the resistor 47 also connected to the line 3. The block 42 is disposed between the output 12 and the line 3 having

  its service voltage connections.

  Operational amplifier 36 controls, via

  of transistor 39, the field effect transistor 33 so

  re that a constant current flows through the inverter 4 and the resistor 34 in the service current connection of the voltage regulator 6. The voltage regulator 6 delivers, at outputs 12, 13, a constant voltage. The circuits connected to outputs 12, 13 are supplied with currents necessary for their various operating states, these currents

  orienting themselves according to the different requirements of the process

sus and the order.

  Part of the current from the constant current source 5,

  which circuits do not need, flows through the transis-

  tor 46. The power delivered by the network device to module 1 is shared between the inverter 4 and the regulator 6 respectively between the different consumption stations,

  placed after, described above.

  The alternating service voltage occurring at the bridge diagonal between the two halves of the transistor bridge circuit is applied, via the capacitors 22, 25, to the input of the rectifier bridge circuit 24 which rectifies

  voltage. The rectified voltage is smoothed by the condensa-

  tor 29 and the suppressor coils 30, 31 and

  is stabilized by the Zener diode 32. The components emit-

  sensors and receivers 7 connected to lines 10, 11, benefit

  because of this stabilized DC voltage.

  Figure 4 shows another embodiment of a wavy

  their, the same elements between the embodiments

  shown in fig. 2 and 4 being given the same references

  these. A correspondence between the inverters according to fig. 2 and 4 is found in the arrangement of the transistor bridges, of the capacitors 22, 25, of the rectifier bridge circuit 24, of the capacitor and of the suppressor reactance coils 30, 31 as well as of the Zener diode 32. In the representation of fig. 4, the transistor 33 of the constant current source 5 is deleted. Instead of

  transistor 33, the voltage is taken at the resistor

  tance 34 and is applied to a voltage to frequency converter 41 which thus generates a frequency which is a function

  of the voltage drop of the resistor 34.

  The control voltage having this frequency controls a

  circuit 46 which generates two triangular voltage repetitions

  res phase shifted by 180 which are respectively applied to the bases of the transistors 17, 19 respectively 18, 20. Due to the voltage drop at the resistor 34, the currents are directed by the capacitors 22, 25 allowing a high rate of availability of the inverter 4. The effective value of the measured quantity is therefore the voltage at resistor 34. If the voltage increases at resistor 34, the frequency is decreased, that is to say in the event of more voltage

  network device, changing the reaction

  This results in the flow of a constant current.

  The inverter 4 is therefore a part of the direct current source which varies in the reactance in order to ensure the current

  constant in case of variable input voltage.

  Figure 5 shows another embodiment of a

  inverter 48 regulating the DC output voltage. The undu-

  also understands them, like the inverter shown in

  fig. 4, the transistors 17, 18, 19, 20 of device identi-

  that and the capacitors 22, 25 to which the rectifier bridge circuit 24 is connected. The effective value of the

  measured quantity is the DC voltage measured at the

  connections 8, 9 and sent to a voltage to frequency converter 47 delivering a control voltage to the circuit 46. The control voltage has a frequency which is a function of the DC voltage at the outputs 8, 9. At a certain DC output voltage for example 5 V, which must be regulated, corresponds to a certain frequency of the voltage converter

continuous in frequency 47.

  If the effective output DC voltage deviates from the theoretical DC output voltage, the frequency is changed. The DC voltage converter 47 precedes circuit 46 which generates the two voltage repetitions phase shifted by 180 for the circuit

transistor bridge.

  If the DC output voltage decreases, the frequency

  increases so that the DC output voltage returns

ne at the set value.

  The transistor bridge circuit is connected in parallel with a Zener diode 48 which, depending on the load, absorbs the

current.

  The constant current is adapted to the power absorbed as much as possible by the transmitting and receiving elements and by the circuit 14, this barely differing from the

minimum power.

  In the arrangement shown in fig. 5, the transistor bridge circuit is placed between lines 2, 3. If an additional DC voltage is required in the respective modules, this must be separated from the potential of the first DC voltage, it is necessary to plan a

  other voltage regulator which can also be an undu-

  their. Thus, the power dissipations based on the generation of regulated direct voltages can be greatly reduced, these power dissipations representing the main part of the thermal stresses to which the input and output modules are subjected in the others.

parts of the circuit.

Claims (7)

CLAIMS:   1. Circuit device for generating operating voltages for modules of input and / or output elements of automation devices which are connected in particular to a central module, characterized in that between the poles an inverter (4, 48) is mounted on a DC voltage source   decoupled output and a voltage regulator generating a voltage   voltage lower than the voltage of the conti- nuous voltage source naked.   2. Circuit device for generating operating voltages for modules of input and / or output elements of automation devices which are connected in particular to a central module according to claim 1, characterized in that between the poles of a DC voltage source are mounted in series an inverter (4) with an ohmically decoupled output, a constant current source (5) and a voltage regulator (6) generating, by parallel stabilization, a voltage continuous which is less than the source voltage of continuous voltage.   3. Circuit device for generating operating voltages for groups of input and / or output elements of automation devices which are connected in particular to a central module according to claim 1, characterized in that 'between the poles of a DC voltage source are   connected in parallel an inverter (48) with a disconnected output   capacitively folded and a voltage regulator that generates a voltage that is less than the voltage of the DC voltage source.   4. Circuit device according to claims 1 and 2 or 3,   characterized in that the rectifier (48) comprises a bridge circuit with non-contact circuit elements (17, 18, 19, 20) and in that the bridge diagonal is connected by   capacitors (22, 25) at the inputs (23, 26) of a rectifier   bridge bridge (24) which are mounted after the smoothing element.   5. Circuit device according to one of claims 1 to 4,   characterized in that the smoothing elements are connected to the operating voltage connections of transmitting elements   and / or receivers (7) for a transmission channel.   6. Circuit device according to claims 1, 2 or 4,   characterized in that the constant current source (5) comprises the inverter (4) connected in series with a resistor   (34) and in that the voltage at the resistor (34) is applied   quée, as an effective value of the adjusted quantity, to a voltage to frequency converter (41) which is connected, on the output side, to a circuit (46) to generate two rectangular phase-shifted voltages of 180 'which are each applied to a pair of transistors (17, 19; 18, 20) of the circuit in inverter bridge (4).   7. Circuit device according to claims 1, 3 or 4,   characterized in that the DC output voltage at   smoothing elements is applied, as an effective value   tive of the magnitude set, to a voltage-to-frequency converter (47) whose frequency modifies the duration of switching on of the non-contact circuit elements (17, 18, 19, 20) of the inverters (48) in the direction of '' a reduction in deviation adjustment.