DE2343176C2 - Magnetic amplifier - Google Patents

Description

the same magnet system both the positive and 95 as well as the negative half-wave of the alternating supply voltage

can be controlled. This is achieved in that in the feed lines of the working winding a further controllable changeover switch is arranged in each case, which when the first switch is closed

The invention relates to a Magnetver- 30 interrupts the feed line and when it is open stronger. first switch reverses the working winding. The arrival

With magnetic amplifiers, the voltage goes to the number of the otherwise necessary working winding to control both half-waves the transductor choke does not come with the agile magnetic components Half of the AC supply voltage through zero, reduce this arrangement by half, a white but rather it approaches as a result of the remanence-related advantage can be seen in the fact that there are no lower values Storage effect of the throttle of the zero line only different temperature drift for the two half-welasymptotically. This is in FIG. 1 occurs in a diagram len, since both the same magnet system through schematically shown, on the abscissa is the time i, flow.

on the ordinate the voltage U _A over the working The invention is plotted on the basis of two circuit windings. 40 examples of a voltage-controlling magnetic amplifier

The incomplete demagnetization to the Zeitker with a half-wave rectifier to the suppression point of the zero crossing of the alternating supply voltage kung of a half-wave of the alternating supply voltage im conditionally either a cut-off frequency of the feed working group explained in the F i g. 2 and 3 intestinal alternating tension, which must be so low are placed.

that at the beginning of the next half-wave the span 45 Fig. 2: A magnetic amplifier contains voltage V _A is known to have reached zero or that at a higher frequency a controllable choke Dr, the working winding quenz a superposition of magnetization and w _A and a control winding w _s has. The choke demagnetization and the resulting Un- Dr is accepted by a direct current source G safety in the voltage curve and the control winding w _s must be flown through. 50 premagnetizes the current and thus the current flow

On the other hand, the highest possible frequency of the working winding w _{A should} be aimed for in the sense of an amplifying supply voltage, since it is influenced by the magnetic distortion. The working coil W _A of the throttle more higher gain is achievable, the Dr is the environmentally feeding lines L and L 'with a square-wave alternating Swept is made of a supply voltage source SP via the time constant T of the magnetic system is proportional to the supply frequency, fed below 55 voltage. In order to achieve the voltage-controlling supply and the quality factor, which is proportional to the supply hold, is, as is known, when the line voltage frequency is greater. train L a diode D arranged as a half-wave rectifier

There is accordingly the task of creating a magnetic net. The load resistance R ₁ lies in the other amplifier so that it can be improved without the supply line L '. Parallel to the main winding _A w th drawbacks with a supply voltage of higher frequency 60 is operable between the supply lines L and L 'in switch frequency. Sl arranged, a second switch S 2 in the course of

The solution to the task is characterized by a control circuit. Both switches are preferably electronic first controllable switches that control the work and form part of the switching device winding in time with the supply / voltage frequency at device K, which is short-circuited by the supply voltage source SP and a second control 65 is controlled.

switch that is in push-pull to the first switch The function is as follows: With the steep back

the control circuit opens or closes. edge of the feeding square-wave alternating voltage

By short-circuiting the working winding, the first switch S1 is closed and thus the ar-

<t

heating coil w _A short-circuited, so that the degaussing in a short time is performed simultaneously the switch 51, the second switch 52 is opened in the control circuit in push-pull to the working rhythm, so that in the control winding _s w no current pulse from the working coil W _A forth can be transmitted. At the beginning of de; In the next positive half-cycle at the working winding υ _A , switch 51 is open again and switch 52 is closed.

Fig. 3: In a further development of the circuit arrangement of each Fig. 2, a further controllable changeover switch 53 and 54 is arranged in each of the feed lines L and L ' , these switches 53 and 54 have, in addition to their end positions a3, c3 and α4, is c 4 still have a middle position 63 or i> 4 and are also actuated by the switching device K.

The switching state of all switches shown corresponds to that in the case of a positive half-wave of the alternating supply voltage SP, switch 51 is g-open, ao switch 52 is closed, switches 53 and 54 are in their positions a3 and ö4 and connect the working winding w _A to the Supply voltage source 57 \

At the zero crossing of the half-wave, as already in Fi g. 2, the switch 51 is closed, the switch 52 is open, the switches 53 and 54 go to their positions i> 3 and 64 and interrupt the feed lines L and L ', respectively.

After the zero crossing, the switch 51 opens and the switch 52 closes; the switches 53 and 54 switch to their positions c3 and cA and thus reverse the working winding w _A , so that the negative half-wave can also be controlled in the same direction as the positive.

The switch arrangement according to the invention can also be used in current-controlling magnetic amplifiers in this case only the control and work windings are in a known manner to be dimensioned differently, and the rectification in the feed circuit is omitted.

1 sheet of drawings

Claims (3)

The Demagnetisieningjäer throttle forced, it leaves patent claims: sicn set a fixed value, so that the initial conditions for the following cycle constant 1. Magnetic amplifier, are marked. The time period At (see Fig. 1), that is the time through a first controllable switch (Sl), 5 between the zero crossing of the supply voltage and the working winding (wj) in time with the supply NuUübergang the voltage U _A at the working winding voltage frequency Zero crossing short -ening, can be greatly reduced to the time Δ f. This closes and a second controllable switch in turn allows a considerable increase in the (S 2), the push-pull to the first switch (Sl) supply voltage frequency with the control circuit already mentioned ( G, w _s ) opens or closes. io benefits. 2. Magnetic amplifier according to claim 1, characterized in that in order to achieve the required short switching times that in the feed lines (L, V) , electronic switches of the working winding (η · _λ ) are preferably used, which are part of a controllable from the supply voltage Changeover switch (S3, S4) is arranged, controlled switching device are. The 15 when the first switch (S1) is closed. The supply voltage is preferably an alternating supply line (L, LO interrupted and when open voltage with a steep trailing edge of the half-wave to the netem switch (S1 _{) use the ATbCItSWiCkIuHg (W 4} ), for example a square alternating voltage . well, with the trailing edge in per se known 3. Magnetic amplifier according to claim 1 or 2, way used to control the switching device characterized in that the supply voltage is so. an alternating voltage with a steep trailing edge of the The favorable properties of the invention Half-wave is and that the switches (S1, S2, S3, magnetic amplifier according to the present invention allow a further training S 4) can be controlled with this trailing edge. to which it is possible to reverse the polarity with