DE2527342B1

DE2527342B1 - Transductor circuit arrangement

Info

Publication number: DE2527342B1
Application number: DE19752527342
Authority: DE
Inventors: Heinz Steuerthal
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 1973-08-30
Filing date: 1975-06-19
Publication date: 1976-09-16

Description

Die Transduktor-Übertrager-Einheit T in der Schaltung nach Fig. 1 besteht aus einer an eine Wechselspannungsquelle UE anzuschließende Primärwicklung 1, in der die Arbeitswicklungen der Transduktoren und die Primärwicklung des Transformators zur galvanischen Trennung von Eingang und Ausgang der Transduktor-Schaltungsanordnung vereinigt sind, der auf einen eigenen Eisenkern gewickelten Ausgangswicklung 11 und den auf je einen Sättigungskern gewickelten Transduktor-Steuerwicklungen 111 und IV. Ein Verbraucherwiderstand Ra ist über einen Ladekondensator C1 und eine Gleichrichter-Brückenschaltung GJ 1 an die Ausgangswicklung II des Transduktor-Übertragers angeschlossen. In den Wechselstromteil zwischen der Ausgangswicklung des Transduktor-Übertragers und der Gleichrichterschaltung G11 ist die Primärwicklung eines Stromwandlers Üeingeschaltet, dessen Sekundärwicklung über eine weitere Gleichrichterschaltung G12 und einen Ladekondensator C2 die Steuerstromquelle für den Steuerkreis mit den Transduktor-Steuerwicklungen III, IV bildet. Die Spannung am Ladekondensator C2 ist durch eine Zenerdiode Z stabilisiert. Mit den beiden Steuerwicklungen III und IV des Transduktor-Übertragers sind im Steuerkreis eine Sperrdrossel Dr und ein Widerstand zur Kompensation der Temperaturabhängigkeit der Steuerwicklungen in Reihe geschaltet. The transducer-transformer unit T in the circuit according to FIG. 1 consists of a primary winding to be connected to an AC voltage source UE 1, in which the working windings of the transducers and the primary winding of the transformer for galvanic separation of the input and output of the transducer circuit arrangement are united, the output winding 11 wound on its own iron core and the one wound on a saturation core each Transductor control windings 111 and IV. A load resistance Ra is across a charging capacitor C1 and a Rectifier bridge circuit GJ 1 to the output winding II of the transducer transformer connected. In the AC part between the output winding of the transducer transformer and the rectifier circuit G11, the primary winding of a current transformer is switched on, its secondary winding via a further rectifier circuit G12 and a charging capacitor C2 the control current source for the control circuit with the transducer control windings III, IV forms. The voltage at the charging capacitor C2 is stabilized by a Zener diode Z. With the two control windings III and IV of the transducer transformer are in the control circuit a blocking throttle Dr and a resistor to compensate for the temperature dependence the control windings connected in series.

Bei stromsteuernden Transduktoren für konstanten Ausgangsstrom treten sowohl an den beiden Steuerwicklungen 111, IV als auch an der im Steuerkreis liegenden Sperrdrossel Dr erhebliche Spannungsspitzen auf. Diese prinzipiell unvermeidlichen Spannungsspitzen stellen sich als Amplituden einer exponentiell abklingenden der Rechteckspannung überlagerten Schwingung dar. Sie sind vom Verhältnis der Windungszahlen der Steuer- zur Arbeitswicklung abhängig und können den vielfachen Wert der übersetzten Eingangsspannung annehmen.With current-controlling transducers, step for constant output current both on the two control windings 111, IV and on the one in the control circuit Blocking reactor Dr causes significant voltage peaks. These inevitable in principle Voltage peaks represent themselves as amplitudes of an exponentially decaying Square-wave voltage superimposed oscillation. They are from the ratio of the number of turns the tax to labor winding dependent and can be many times the value of the translated Accept input voltage.

Aus dieser Abhängigkeit folgt, daß die Windungszahl N1, N2 der Steuerwicklungen möglichst niedrig sein muß, um die Spannungsspitzen klein zu halten. Für eine vorgegebene Durchflutung bedeutet dies einen entsprechend großen Steuerstrom Js Diese Forderung läßt sich beim fremdgesteuerten Transduktor leicht erfüllen, da Ausgangs- und Steuerkreis voneinander unabhängig dimensioniert werden können. Die Verwendung des Stromwandlers Ü gestattet mit Hilfe seines Übersetzungsverhältnisses die freie Wählbarkeit des Steuerstromes Is bzw. der Windungszahl der Steuerwicklungen. Sollen Spannungsspitzen an den Steuerwicklungen um einen bestimmten Faktor reduziert werden, so sind lediglich das Übersetzungsverhältnis von Sekundär- zu Primärwicklung des Stromwandlers Ü und die Zenerspannung einer den Ladekondensator überbrückenden Zenerdione zu verringern. From this dependency it follows that the number of turns N1, N2 of the control windings must be as low as possible in order to keep the voltage peaks small. For a given Flooding, this means a correspondingly large control current Js This requirement can easily be fulfilled with externally controlled transducers, as the output and control circuit can be dimensioned independently of each other. Using the Current transformer With the help of its transmission ratio, Ü allows the free selection of the Control current Is or the number of turns of the control windings. Should voltage peaks at the control windings are reduced by a certain factor, so are only the transformation ratio of the secondary to the primary winding of the current transformer Ü and to reduce the Zener voltage of a Zenerdione bridging the charging capacitor.

Mit der Zenerdiode, die auch durch einen Querregler ersetzt werden kann, und dem Widerstand Ri des Stromkreises wird der in den gegeneinandergeschalteten Steuerwicklungen fließende Steuerstrom Js festgelegt, von dessen Konstanz die des Ausgangsstromes abhängt. Die Größe des Ausgangsstromes wird durch die Gleichstromdurchflutung dieser Drosseln bestimmt. With the zener diode, which can also be replaced by a cross regulator can, and the resistance Ri of the circuit is that in the oppositely connected Control windings flowing control current Js set, of whose constancy that of the Output current depends. The size of the output current is determined by the direct current flow of these chokes.

Mit der Einführung des Stromwandlers ergibt sich eine galvanische Trennung von Steuerkreis und Arbeitskreis. Damit ist gleichzeitig eine Forderung für diejenigen Schaltungen erfüllt, bei denen die Zenerdiode durch eine Regelschaltung oder integrierte Schaltungen ersetzt wird. With the introduction of the current transformer, there is a galvanic Separation of the steering group and the working group. This is also a requirement met for those circuits in which the zener diode is controlled by a control circuit or integrated circuits is replaced.

Die Wirkungsweise der Schaltung nach F i g. 2 ist praktisch die gleiche wie die der vorstehend beschriebenen Schaltung nach F ig. 1. Schaltungsmäßig unterscheiden sich die Ausführungsbeispiele dadurch, daß in der Schaltung nach F i g. 2 ein selbständiger Stromwandler für den Steuerkreis eingespart ist und durch seine Einbeziehung in die Transduktor-Übertrager-Einheit nur als eine zusätzliche Ausgangswicklung V der Transduktor-Übertrager-Einheit T1 mit eigenem Eisenkern in Erscheinung tritt. Auch hier wird die Spannung der Ausgangswicklung Vgleichgerichtet und mittels einer Zenerdiode Z stabilisiert. Alle mit der Schaltung in F i g. 1 übereinstimmenden Schaltungsteile sind mit den gleichen Bezugszeichen versehen. The mode of operation of the circuit according to FIG. 2 is practically the same like that of the circuit described above according to FIG. 1. Differentiate in terms of circuitry the exemplary embodiments are characterized in that in the circuit according to FIG. 2 a self-employed Current transformer for the control circuit is saved and due to its inclusion in the transducer-transformer unit only as an additional output winding V der Transductor-transformer unit T1 appears with its own iron core. Even here the voltage of the output winding V is rectified and by means of a Zener diode Z stabilized. All with the circuit in FIG. 1 matching circuit parts are provided with the same reference numerals.

Claims

Claims: 1. Transductor circuit arrangement, consisting of two transductor chokes, each with a work and control winding, the one on the consumer side Output from an AC voltage source at the input of the transducer circuit arrangement is galvanically separated, the transductor chokes and a galvanic Separation between the input and output of the transformer used to form a transducer-transformer unit are combined in such a way that one as a transductor working winding and a transformer primary winding acting common input winding (primary winding) via at least three closed Iron cores is wound, two of which are designed as saturation cores one transductor control winding and at least one further iron core an output winding (Secondary winding) for the consumer circuit, according to patent 2343815.5, characterized in that the transducer circuitry is independent of the The size of its output direct current is operated in a self-exciting circuit, in such a way that that the control current for the transductor control windings (III, IV) by means of a Transformer (Ü) in connection with a rectifier circuit (12) from the output alternating current derived from the transducer circuit arrangement and constant by a control circuit (Z) is held.

2. Transductor circuit arrangement according to claim 1, characterized in that that the primary winding of the transformer designed as a current transformer (Ü) with the Output winding (secondary winding) (II) of the transducer-transformer unit (T) connected in series and the secondary winding of the transformer (ü) via the rectifier circuit (G 12) connected to the series connection of the transducer control windings (III, IV) is.

3. transductor circuit arrangement according to claim 1 or 2, characterized characterized in that the transformer in the transductor-transformer unit (Tl) with is included in such a way that another, with the primary winding of the transducer-transformer unit Magnetically coupled closed iron core with a winding (V) as a power supply source for the transducer control windings (III, IV).

The invention relates to a transducer circuit arrangement, consisting of two transducer chokes with one working and one control winding each, whose consumer-side output from an AC voltage source at the input of the Transduktor circuit arrangement is galvanically isolated.

According to the main patent 2343 815, the effort for the implementation galvanic isolation between input and output of transducer circuits simplified by the fact that the transductor chokes and one for galvanic separation Transformer used between input and output to form a transducer-transformer unit are summarized in such a way that one as a transductor ar- part winding and as transformer primary winding acting common input winding (primary winding) via at least three closed Iron cores is wound, two of which are designed as saturation cores One transductor Steiierwickel each and at least one further iron core an output winding (Secondary winding) for the consumer current.

Such a transductor circuit arrangement can be used to avoid its own supply source for the delivery of a control current for the control windings the transducer-transformer unit can also be designed in a self-exciting circuit. when the ampere turns ratio of the control windings to the working windings of the transductor chokes is larger than one during the run-up and the control windings via a rectifier at the output of the transducer-transformer unit are connected in series with a load resistor. As in such a self-exciting circuit the control windings in the steady state almost from the entire output current (load current) is flowed through, the number of turns ratio of primary winding to control winding the transducer-transformer unit can no longer be freely selected.

The invention is based on the object of eliminating this dependency.

This object is achieved according to the invention in that the transductor circuit arrangement operated in self-excitation circuit regardless of the size of their output direct current is such that the control current for the transductor control windings by means of a Transformer in connection with a rectifier circuit of the output alternating current derived from the transductor circuit arrangement and constant by a control circuit is held. The primary winding of the transformer designed as a current transformer is connected to the output winding (secondary winding) of the transducer-transformer unit connected in series and the secondary winding of the transformer via the rectifier circuit connected to the series connection of the control windings.

According to an advantageous development of the invention, the transmitter, which supplies the control current, is included in the transductor-transformer unit be in such a way that another, with the primary winding of the transducer-transformer unit magnetically coupled closed iron core with a winding as a power supply source for the transducer control windings.

Further details of the invention are based on FIGS 2 explained in more detail.

In Fig. 1 is a current controlling transductor circuit arrangement for constant output current using a transducer-transformer unit and a transformer designed as a current transformer for the self-excitation of the Circuit shown.

In the circuit according to FIG. 2 is the current transformer in the transducer-transformer unit included.