FR2702894A1 - Circuit of a two-wire switch. - Google Patents

Abstract

The object of the invention is a two-wire switch circuit for establishing and cutting the power supply to a load supplied by the mains. The circuit comprises an electronic load break switch (6); a control circuit (7) whose output (AS t) is connected to the control terminal of the switch (6) and coupling means (RV, Cg l, 13) which prefix a phase angle (beta) determined in each half-wave of the mains voltage (UN), while the circuit (4) is supplied with voltage and the current flow by the load is interrupted, so that the allowable conduction angular range is fixed as the difference d 'phase angle of full half-wave (180 degree) of the mains voltage (UN) and the pre-set phase angle. Applicable to electrical installations.

Description

Two-wire switches are frequently used in

  electrical installations to establish

  and cut off power to a load A problematic aspect

  This application is the supply voltage of the switch: when it is closed, the voltage between the input and output terminals of the switch is equal to zero in the ideal case, which means that there is no voltage available for

  the power supply of the switch itself.

  t 10 Circuits for making such interrupts

  two-wire transmitters by means of bidirectional

  The triacs, bi-directional semiconductor switches (diacs) and resistance and capacitor elements have the disadvantage that there is no inexpensive option to switch off the switch at will, so that electronic security (cutoff

  in case of overload) is also not possible.

  The object of the invention is to indicate a circuit of a bifilar interrupteir, serving to establish and cut the power supply of a load supplied by the

  alternating voltage of the sector, by means of which the

  The voltage distribution of the two-wire switch may be prefixed, in the case where an AC voltage is used as drive voltage, in a flexible manner and

automatic.

  According to the invention, this result is obtained by the fact that such a circuit comprises: a) a load-breaking electronic switch, b) a control circuit realized in the form of an integrated circuit and the output of which control is connected to the control terminal of the electronic switch, as well as c) coupling means which prefix a phase angle determined in each alternation of the AC voltage of the sector, while the circuit is supplied with voltage and the circulation current through the load is interrupted, so that the range

  angle of circulation of the self-charging current

  Reason is set as the phase angle difference of the full alternation of the ac mains voltage and the prefixed phase angle. According to another advantageous characteristic, an operating unit prefixes the phase angle in each alternation of the AC voltage of the sector as a function of the minimum voltage requirement of the circuit, so that the angular range of current flow

  allowed load takes its maximum value.

  An advantageous embodiment of the circuit according to the invention provides that the integrated control circuit comprises the following components:

  a) connection terminals constituting an input of

  a synchronization input and a control output,

  b) a window voltage discriminator connected to the

  power supply and serving as an operating unit for prefixing a first threshold and a second threshold,

  c) a voltage comparator connected to the sync input

  chronization and serving as synchronization unit to prefix a third threshold,

  (d) piloting logic, linked to the output of the

  window tension criminator and at the exit of the

  voltage comparator, the logic that drives the

  Switching behavior of the electronic switch

  tronic according to the voltage applied to

  the power input or at the synchronization input

  tion, and e) a final stage connected to the output of the logic of

  piloting and whose exit forms the exit

  floor. Another characteristic provides that the window discriminator generates a validation signal and transmits this signal to the control logic when the voltage applied to the power supply reaches

  the first discriminator threshold, and that the comparison

  The generator generates an output signal that suppresses the enable signal when the voltage applied to the sync input reaches the third threshold.

  Yet another characteristic of the invention

  tiorn provides that the window discriminator generates, as an output signal, a control signal and transmits this signal to the control logic when the voltage applied to the supply input drops.

  below the second threshold of the discriminator

  be, and that the control signal of the window discriminator changes the angular range of circulation of the

load current allowed.

  As indicated above, coupling means of the circuit prefix in each alternation of the

  AC voltage of the sector a phase angle, which sets the angular range of conduction or angular range of circulation of the authorized charging current, or the maximum angle (of conduction) possible for the circula-

  charging current, as a difference in load angle between the full alternation of the mains AC voltage and the pre-fixed phase angle The phase angle and therefore also the angular range of the charging current flow permissible in each alternation of the mains AC voltage as a function of the voltage requirement of the circuit (including the on-load electronic switch and the control circuit). It is advantageous if the phase angle is prefixed. in accordance with the minimum circuit voltage requirement, which means that the supply voltage corresponding exactly to that required at the minimum is made available to the load break switch and the driver circuit; the angular range of circulation of the authorized charging current can take its greatest possible value in this case The angle (real) of circulation of the charging current can be chosen

  freely within this allowed range.

  The phase angle depends on the voltage step of two voltages derived from the AC voltage of the

  power supply (mains voltage and synchro-

  tion) and is set by a first threshold controlling the supply voltage and a third threshold controlling the saturation voltage of the on-load switch: if the supply voltage reaches the first threshold, the supply voltage of the pilot circuit

  is ensured, so that the validation for the circulation

  current flow by the load can take place; if the voltage on the load cut-off switch drops below the third threshold, the enable is canceled and the current flow through the load is blocked In addition, when a second threshold, controlling the supply voltage , is reached, the delay angle to the control and hence the angular range of circulation of the allowed charging current, can be varied to ensure the voltage supply.

  it is preferable to use a window discriminator to monitor the first and second threshold and a comparator to monitor the third threshold, an input of the discriminator receiving the supply voltage and an input of the comparator receiving the synchronization voltage.

  The output signal of the window discriminator sets the first threshold as the minimum voltage value for enabling the current flow through the load and the second threshold as the lower limit for the permissible supply voltage; the

  comparator output signal sets the lower limit

  for switching on the load break switch and serves simultaneously to synchronize the

  circuit with the zero crossing of the alternating voltage

  outside the phase angle pre-defined by the window discriminator and the comparator, therefore within the permitted phase angle range, the flow angle of the charging current can be chosen and varied according to the needs, for example by means of a cut-off control of the beginning of the alternation or of a command by cut-off of the end of the alternation (control by initial phase shift or by

final phase shift>.

  The on-load electronic switch can be made for example in the form of a transistor and be constituted for example by an IGBT type transistor (insulated gate bipolar transistor), a MOS transistor, a transistor having a transistor effect.

field or a bipolar transistor.

  Other features and benefits of

  the invention will become clearer from the description of

  The following is a non-limiting example of embodiment, and the accompanying drawings, in which: Figure 1 is a block diagram of the circuit; FIG. 2 represents the voltage rate /

  current as a function of time (Figure 2a) and the diagrams

  grams of voltage as a function of time (Figure 2b) in

  the case of an order breaking the beginning of the alter-

  nance; and Figure 3 shows the pace of tension /

  current as a function of time (Figure 3a) and the diagrams

  grams of voltage as a function of time (Figure 3b) in

  the case of an order by break of the end of the alter-

  nance. According to FIG. 1, the load or the receiver 3 is powered by the AC voltage of the sector UN through the two lines (two-wire line) 1, 2; for a defined voltage supply, the circuit is provided

  4, comprising the rectifier 5, the electronic switch

  The integrated circuit 7 has a six-pin connection pin 6, which is constituted according to FIG. 1, for example by an IGBT transistor, and the control circuit 7 consists of an integrated circuit. (whose pin P forms the supply input EV for supply with the supply voltage Uv, the pin P 2 forms the synchronization input E Syn for the synchronization voltage U Syn 'the pin P forms the control output A Str pin P 4 forms the safety output As, pin P 5 has the reference potential (ground GND) and pin P 6 forms the control input Is This circuit 4 o has several components or parts , namely a power supply 8 (for the voltage supply of the integrated circuit), a power-up circuit 9 (which sets the initial conditions), a control logic (for operation and control of the process flow in time), a security 11 with a

  detection resistance Rdét for this security (service

  The remaining components of the integrated circuit 7 are a timing unit 12 consisting of a comparator and an operating unit 13 consisting of a window discriminator. The input of the comparator 12 is connected to the pin P 2 (synchronization input E Syn), the input of the window voltage discriminator 13 is connected to the pin P (power input Ev) and their outputs are connected to the control logic 10 discriminator 13 sets two voltage thresholds U 1, U 2 and the comparator 12 sets a third

  voltage threshold U 3 Discrimination output signals

  window 13 and comparator 12 are generated according to the shape of the supply voltage Uv and the synchronization voltage Usyn with respect to the thresholds U 1 i U 2 and U 3 and these signals are sent to the logic 10 As the transistor 35 IGBT 6 is a polarized switch, the AC voltage of the sector UN must be rectified by means of a control device 10 (by which the load-breaking switch 6 is enabled).

of the rectifier 5.

  The voltage relationships will be explained below.

  as a function of time with reference to Figure 2 (

  cut-off of the beginning of the alternation) and the

  figure 3 (command by cut of the end of the alter-

  nance) Figure 2a shows the voltage / current curve as a function of time and Figure 2b shows the voltage vs. time diagram for a circuit using the cut control of the beginning of the alternation, while the FIG. 3a shows the voltage / current curve as a function of time and FIG. 3b shows the voltage vs. time diagram for a circuit using the cut-off control of the

end of alternation.

  In the case of the cut control of the beginning of the alternation, the following temporal behavior is obtained:

  1) At the beginning of each alternation of alternating voltage

  In the sector UN, the smoothing capacitor Cgl is loaded through the series resistor RV and this voltage is applied as the supply voltage U to the pin P of the integrated circuit 7 When the UV supply voltage reaches the first threshold U 1 (phase angle B, time t according to FIGS. 2a, 2b), the control logic 10 is enabled by the output signal of the window discriminator 13; the transistor IGBT 6 can now be made conductive by the pilot output A St of the integrated circuit 7 (pin P 3) and the circulation of a charge current I 3 through the receiver 3 can be enabled (maximum angle of circulation). charging current O max or

  maximum angular range permitted for the circulation

charging current).

  2) The effective angle O for the flow of the charge current is chosen in accordance with the receiver voltage requirement (time t 2 according to FIGS.

and 2 b).

  3) If the voltage U Syn at the synchronization input E Syn (pin P 2) this voltage is obtained by the synchronization resistors R Syn1 'R Syn2 from the alternating voltage of the network UN drops below the third threshold U 3 (time t 3 according to FIGS. 2 a, 2 b), this event is interpreted by the zero crossing of the AC voltage of the sector UN and the circulation of the charging current I 3

  is stopped by the deletion of the validation signal

  for the control logic 10 (blocking the

IGBT transistor 6).

  In the case of the cut-off control of the end of the alternation, the following temporal behavior is obtained: 1) At the application of the voltage of the sector UN through the load 3 to the bifilar switch, not yet engaged, the UV supply voltage of the integrated circuit 7 is established and this UV voltage rises significantly above the first threshold U

  2) When the load cut-off switch 6 is

  latched, the whole of the alternation can first be chosen for the conduction angle (O = 1800)

  until UV reaches the second threshold U 2.

  3) When the supply voltage Uv goes below the second threshold U 2 (Uv <U 2), the conduction angle θ is reduced, step by step, until the supply voltage UV reaches the first threshold U 1 (Uv = U 1). 4) This value of O at the moment the first threshold U is reached is defined as the angular range of

  allowed conduction O max and "frozen" l.

Claims (8)

  1 circuit (4) of a two-wire switch for switching on and off the supply of a load (3) powered by the AC mains voltage (UN), characterized in that it comprises: a) a cut-off electronic switch in charge (6), b) a control circuit (7) realized in the form of an integrated circuit and whose control output (Ast) is connected to the control terminal of the electronic switch O (6) , as well as c) coupling means (Rv, Cgl, 13) which prefix   a phase angle (B) determined in each alter-   AC mains voltage (UN), while the circuit (4) is supplied with voltage and   the flow of current through the load is inter-   broken, so that the angular range of circula-   permissible load current (Max) is set as the phase angle difference of the full alternation (180) of the   sector (UN) and the prefixed step angle (B).   Circuit according to Claim 1, characterized in that an operating unit (13) prefixes the phase angle (B) in each alternation of the AC voltage of the sector (UN) as a function of the minimum voltage requirement of the circuit. (4), so that the angular range of circulation of the allowed charging current (O max) takes its maximum value.   Circuit according to claim 1 or 2, characterized   characterized in that the control integrated circuit (7) comprises the following parts or components: a) connection terminals (PL, P 2, P 3) constituting a   input supply (Ev), a synchronization input   (E Syn) and a pilot output (Ast), b) a window voltage discriminator (13), connected to the supply input (Ev) and serving as an operating unit for prefixing a first threshold (U 1) and a second threshold (U 2), c) a voltage comparator (12) connected to the synchronization input (Esyn) and serving as a synchronization unit for prefixing a third threshold (U 3) , d) a control logic (10) connected to the output of the window voltage discriminator (13) and to the output of the voltage comparator (12), which controls the   switching behavior of the electrical switch   tronic (6) depending on the voltage (Uv or Usyn)   applied to the feed inlet (Ev) or to the   synchronization (Esyn), and e) a final stage (14) connected to the output of the control logic (10) and whose output forms the output of piloting (Ast).   Circuit according to Claim 3, characterized in that the window discriminator (13) generates a validation signal and transmits this signal to the control logic (10) when the voltage (Uv) applied to the power input ( EV) reaches the first threshold (U 1) of the discriminator (13), and the comparator (12) generates an output signal which suppresses the signal of   validation when the voltage (Usyn) applied to the   synchronization (Esyn) reaches the third threshold (U 3).   Circuit according to Claim 4, characterized in that the voltage (Uv) at the supply input (EV) is obtained from the AC mains voltage (UN) by means of a series resistor (Rv). and a smoothing capacitor (Cgl).   Circuit according to claim 4 or 5, characterized   in that the voltage (U Syn) at the input of syn-   Chronization (Esyn) is obtained from the AC voltage of the sector (UN) using resistors from synchronization (Rsynlr Rsyn 2). he   Circuit according to any one of the claims   1 to 6, characterized in that the window discriminator (13) generates, as an output signal, a control signal and transmits this signal to the control logic (10) when the voltage (Uv) applied to the control signal. supply input (EV) drops below the second threshold (U 2) of the window discriminator (13), and the control signal of the window discriminator (13) changes the angular range of current flow allowed load (max).   Circuit according to any one of the claims   1 to 7, characterized in that it comprises a   trainer (5) for rectifying the AC voltage of the sector (UN).   Circuit according to any one of the claims   1 to 8, characterized in that the load-breaking electronic switch (6) is constituted by an IGBT type transistor.   Circuit according to any one of the claims   1 to 8, characterized in that the load-breaking electronic switch (6) is constituted by a field effect transistor.