DE859033C - Circuit for generating periodic electrical energy pulses - Google Patents

Description

"(WiGBI. P. 175)

ISSUED DECEMBER 11, 1952

B ii / SoVIIIa / sia ¹

has been named as the inventor

The invention relates to electrical circuits for periodically generated energy pulses from steep increase under load.

The proposed invention is particularly suitable for such cases when the load is about in devices such as B. a magnetron or part of a nuclear particle accelerator, exists, for which a high energy pulse of short duration is required.

It has already been proposed to use a circuit for this purpose in which a capacitive resistor is charged from the power source and with the load via a Saturation inductance is connected.

The unsaturated impedance of the inductance is compared with during the charging process the impedance of the capacitive resistor is high enough to prevent the capacitive Resistance discharges through a load before the voltage of the capacitive resistance reaches a value which creates a sufficient flux of lines of force in the magnetic core, to satiate him.

When this occurs, the inductance drops to a low value, and the capacitive resistor discharges _r after it has reached a sufficiently high voltage under load. However, there is still some inductance in the circuit; available. The charging voltage needs a certain time to rise to its peak value when under load. For a given capacitor, the time it takes for the voltage to reach their

To reach the maximum value, the greater the ratio of the saturated inductance to the load resistance in the circuit. If the ratio is too small , the unsaturated value of the inductance is also small and the charging of the capacitive resistor is affected.

The factor that determines the increase that can be achieved without the minimum limit ίο the ratio is below the mentioned ratio, determines the value of the permeability of the material in the transition from saturated to unsaturated State.

The invention generally aims to provide an electrical circuit through which a sufficiently large inductance is retained to charge a capacitive resistor, on the other hand, however, the discharge under load due to a relatively small value of the To determine inductance in such a way that there is a steep increase in voltage under load.

According to the present invention, a circuit * for generating electrical Assumed energy impulses under load, which includes capacitances connected in parallel, which are connected between connection and consumer, each adjacent pair of Capacities are inductively connected to each other, whereby a saturation of the core induction occurs.

The characteristic of such a circuit is the gradation of the inductances. marked, such that the circle to be saturated is much higher and the saturated circle is essential Each subsequent circle receives lower values than the unsaturated circle! Inductance towards towards the consumer .. At this resonance formation is the last pair of neighboring Capacities that are coupled to the consumer terminals are not involved.

During operation, the capacitive resistance stores the energy that is used to generate pulses and make up for losses. During charging, a voltage is created in the first inductance circuit developed, which saturates the same and transfers the charge to the neighboring capacitance. Similarly, a higher voltage is developed across this adjacent capacitance. Of the The flux of the lines of force increases in the second inductance circuit, and through saturation the charge of this capacity is transferred to the next and so on until the end of the resonance series, where the voltage is transferred to the consumer. In each circle the time for the transmission decreases, since the inductance of each circuit is less than that of the previous circuit. As a result the decay of the voltage-time integral of the waveform applied to each inductance circuit the necessary linkages of lines of force in the core of the inductance are reduced. They are one Sufficient number of stages switched on as compared to the saturated value of the end inductance to be able to neglect to the consumer. As a result, the voltage on the consumer grows at a relatively greater rate as in a simple case given above, where a resistance aiii the place of occurs through the saturation of the first inductance charged capacitance.

Another feature of the invention is the ability to use one with a frequency modulated Power source connected capacitive resistance, e.g. B. from a power source with sinusoidal voltage wave, in connection with an essentially unidirectional one Power. The first inductance receives an auxiliary winding that connects to a DC power source is connected so that a resulting flux of force lines in the core of the inductance is produced. This has the consequence that every increase in the voltage in the load resistor has the same polarity, because the auxiliary force lines flow through one of the polarities of the charge of capacitive resistance. generated flux of force lines prevents the core of the inductance to satiate. In another embodiment, the direct current can flow into the main winding of the reactance introduced with the help of an appropriate decoupling circuit will.

In the drawings, various embodiments of the subject matter of the invention are for example and shown schematically.

Fig. Ι shows a Schaltscähema an embodiment the subject of the invention;

FIG. 2 shows the characteristic voltages in various parts of the circuit of FIG Fig. Ι;

Fig. 3a illustrates an example of a charging circuit for use in the invention;

FIGS. 3 b and 3 c show the waveform of the voltage in the charging circuit of FIG. 3 a without and with the auxiliary windings, which are drawn in dotted lines;

4 shows a circuit diagram of a second embodiment;

5 shows a network switching scheme according to the invention with η inductances connected in series;

Fig. 6 is a circuit diagram for a four stage network used as a radar modulator;

Fig. 7 shows voltage characteristics of various Parts of the network according to FIG. 6.

_{According to FIG. 1, inductances L 1} , L ₂ , L ₃ provided with magnetic cores to be saturated are connected in series between a terminal of a capacitive resistor C ₁ and a terminal of the load.

A capacitance C ₂ is connected between the connection of the inductances L ₁ and L ₂ and the return line from the load to the capacitive resistance C ₁ . The stimulating network that z. B. is connected as an auxiliary transmission line with series inductances and a shunted capacitance, is connected between the

connection of the inductances L ₂ and L ₃ and the return line switched. The network is thus made up of series-connected inductances and shunted capacitances. The core of the inductances L ₁ , L ₂ , L ₃ consists of a material that has a sharp magnetization characteristic, e.g. B. from 50/50 cold-rolled nickel iron, which gives a magnetization coefficient of the following value:

Tjr L unsaturated

K = - = - r- ⁵ - = 1000 or greater.

L saturated

The inductances L ₁ , L ₂ , L ₃ are graded according to the following law:

- ^ - = ~ = k (unsaturated values),
L ₂ L _s

where z. B. k is at least 10, but not greater than 100 for K = 1000.

Is the capacitance C ₁ can in different, known manner to be loaded, Fig. 3 a shows a typical charging circuit in which the capacitance C ₁ from a source of sinusoidal voltage charged by the Iruduktanz L, the latter is selected such that

^w LC ₁

where ω ² = 2 nf and f is the voltage frequency in Hz or more precisely

ω ^Λ =

LU L + L '

where '. _T , the effective inductance of the inductive

dance series and is the unsaturated inductance of the reactances connected in parallel. 3 b and 3 c show the resulting shape of the charge waves on the capacitive resistor C ₁ .

Since the inductance L _{1 is} large in comparison with the

Inductances: L ₂ and L ₃ , the goes substantially

total voltage across the capacitive resistor C ₁ through the inductance L ₁ .

The inductance L ₁ is designed so that, when subjected to the waveform of the charge voltage, the core is saturated at a voltage which corresponds to the required peak voltage across the capacitive resistor C _1. When the voltage reaches this value, the inductance of L ₁ drops to a low value, and the capacitive resistor C ₁ discharges through this inductance, see above

that the capacitance C _{2 is} charged, the inductance L _{2 being} sufficient to allow a small current to flow during the charging time. If the capacitance C _{1 is} almost equal to the capacitance C ₂ is, as in Maximalspanoung at capacitor C _2, the total energy of the capacitance C ₁ of the capacitor C ₂ is transferred, and the voltage at the capacitance C ₁ becomes zero. This change requires a time which depends on the saturated value of the inductance L ₁ and the effective capacitance of the capacitive resistor C _{1 and the capacitance C 2} lying in series with it. The increase in voltage across the capacitance C ₂ brings about a sufficient change in the flux of force lines in the core of the inductance L ₂ to saturate it, and the inductance falls, as with inductance L _{1, in} such a way that the charge transfers to the next capacitor, which in this case which is the impulse generating network (capacitance C ₃ ), during which time through the inductance. L ₃ flows a current that can be neglected. The time for the voltage increase at the capacitance C ₃ is significantly shorter than the time for the voltage increase at the capacitance C ₂ , since the inductance L ₂ in the saturated state is a smaller inductance than the inductance L ₁ in the saturated state. The voltage changes are shown in FIG. An indexed curve labeled "F" indicates the voltage variation in the element identified by the index. When the capacitance C _{3 is} changed, the inductance L ₃ becomes saturated and the voltage increases in the load resistor at a relatively faster rate as the saturated inductance L _{3 is} a smaller inductance than the saturated inductance L ₂ .

The load can e.g. B. be the ignition circuit of an ignitron discharge tube, in which case the ignition circuit can replace the load or be connected to the secondary winding of a transformer whose primary circuit takes the place of the load in FIG. In this case the capacitance C _{3 would be} a simple capacitor '.

In the case described, the voltage transfer is carried out three times. However, the inductance and capacitor _{stages L 1} , L ₂ ... L _n and C ₁ , C ₂ .. .C _n could be used if faster switching than shown in FIG. 5 is required.

The last inductance is connected so that its saturated inductance is that of a single one Inductance level in the cable unit corresponds to or less than this. Hence it acts as a Switch which has an impedance of sufficiently low value so that the frequency through the Discharge of the network generating the pulse is maintained.

If the capacitive resistor C ₁ , as in the embodiment described, is fed by an alternating current source, the charge applied to the capacitive resistor C ₁ and, as a result, the peak voltages alternately have opposite polarities. A special winding can be placed on the core of the inductance L ₁ (shown in dotted lines in Fig. 1) and fed with direct current to produce a resultant flux of lines of force in the core. If this flux of force lines has a sufficiently high value that prevents the voltage of the corresponding polarity from generating a sufficient flux of force lines.

begets to saturate the core so. the resulting peak voltage across the load resistor will be in one and the same direction. According to Fig. 4, the modified arrangement is shown in which a capacitive resistor C ₁ is charged by an inductance L ₁ to be saturable and the primary winding of a transformer with a saturation core, with a capacitance C ₂ and the primary winding of a second transformer T _{2 in the secondary circuit} Saturation core. In the secondary _{circuit of the transformer T 2} are: the auxiliary cables C ₃ and a load that z. B. illustrated as a magnetron M fed by a transformer T _{3 of} normal type.

The unsaturated primary inductance of the transformer T ₁ is low compared to the unsaturated inductance L ₁ , but high compared to its saturation value. Similarly, the unsaturated value of the primary inductance of the transformer T _{2 is} low compared to the unsaturated secondary inductance of the transformer T ₁ , but high compared to its saturation value. The transformers T ₁ and T ₂ can be designed so that they can be switched on and off in stages, depending on the requirements of the power system. So could e.g. B. in the illustrated radar transmitter, the supplied voltage can be comparatively low, z. B. be several 100 V, and with a gradual increase the voltage pulses communicated to the magnetron can rise to several 10,000 V.

During operation, the capacitive resistor C _{1 is} charged by the current source through the inductance L ₁ , which is expediently in resonance with the capacitive resistor C ₁ at the frequency supplied. During charging, as long as the inductance L _{1 is} unsaturated, the voltage across the primary winding of the transformer T _{1 is} low. At the maximum voltage with capacitive resistance C ₁ , the inductance L _{1 is} saturated, and the capacitive resistance C ₁ discharges through the saturated inductance L ₁ together with the earth fault _{inductance of the transformer T 1} and the primary inductance of the transformer T ₂ , so that the capacitance C _{2 is} loaded.

The value of the capacitance C ₂ is such that, when it is related to the primary side of the transformer T ₁ , its capacitance is almost equal to that of the capacitive resistance C ₁ . The core and the windings of the transformer T ₁ are arranged so that when the voltage across the capacitance C _{2 is} at its maximum, the core of the transformer T _{1 is} saturated and the secondary inductance drops to a value which is low in comparison with the primary inductance of the transformer T ₂ , so that the capacitance C ₃ is charged by the discharge of the capacitance C ₂ by means of this inductance, the earth fault _{inductance of the transformer T 2} and the primary inductance of the transformer T ₃ . As above, at maximum voltage across the capacitance C _3, the secondary winding of the transformer T _{2 is} saturated, so that its saturated value has the size of a single inductance circuit of the cable unit. The capacitive resistances of the cable unit then discharge through this inductance and. the reactive inductance of the transformer T ₃ into the load, which in this case is represented as a magnetron.

1 η Fig. 6 shows a circuit designed according to the invention with four inductance stages, which is used as a radar modulator. The load here is formed by the primary winding of a transformer T, the secondary winding of which is connected in such a way that it excites a magnetron M. Corresponding elements are denoted by the same reference numerals as in FIGS. 1 to 5. A step transformer N is connected between the inductance L and the capacitive resistor C _{1 in} order to achieve the required high voltage.

C ₄ is a stimulating network of inductances and capacities. The distribution of the voltage over the four capacitances during one period is illustrated in FIG. The curve V ₀₁ shows the voltage across the capacitance C ₁ , etc.

Typical values for a circuit of this type are the following: absorbed voltage 80 V, 1500 periods per second; output voltage, Peak voltage = 4 kV, duration of the pulse = 0.25 ^ s.

In some applications where pulses are generated in a single direction and where certain core materials are used for the surge transformers and reactors to be saturated, it is sometimes advantageous to improve the properties and operation of the transformer and reactors by applying a direct current to it, which acts on the cores in such a way that the effects of the large bursts of energy occurring in one and the same direction which occur in the windings during the discharge are to a certain extent compensated for. A direct current circuit acting in this sense is shown at B in FIGS. 3 a, 4 and 6.

Claims (11)

Patent claims: i. Circuit for generating periodic electrical energy pulses, which a number comprised of capacitances connected in parallel between the power supply and load terminals are connected, with two adjacent capacitances inductively mediated are connected to a saturable iron core coil, characterized in that with the exception those coils that have the last pair of adjacent capacitors next to the load terminals, connects, the saturation value of all inductances gradually decreases, in such a way that the saturated value of the preceding one is considerably lower than that unsaturated value of the subsequent inductance, while the unsaturated values in Gradually increase the direction towards the output terminals. 2. Circuit according to claim i, characterized in that that the capacitances and inductances in 'the form of a multiple T-network are arranged, the inductors in series, the capacitances in the shunt. 3. Circuit according to claims ι and 2, characterized in that means are provided for generating a by direct current generated, on the core always in the same ίο in the direction of the force flow. 4. Circuit according to claims 2 and 3, characterized in that the device comprises an additional winding on the core which is supplied with direct current. 5. Circuit according to claims 2 and; 3, characterized in that the device has a direct current circuit which is in series is switched with the inductance winding mentioned. 6. Circuit according to claims 1 and 3, characterized in that the capacitance closest to the power supply terminals is designed so that it can be charged by a choke coil with a saturable core, wherein the device comprises an additional winding on the choke coil connected to Direct current is fed. 7. Circuit according to the claims. 1 to 6, characterized in that the cores are formed from a material which is rectangular Has hysteresis characteristics, e.g. B. from 50/50 cold-rolled nioke iron. 8. Circuit according to claims 1 to 7, characterized in that the first the Clamping the load lying capacitance is the capacitance of a pulse-forming network. 9. A circuit according to claim 7, characterized in that the pulse-shaping network is an auxiliary transmission line or cable whose inductance is in series and whose capacity is shunted. ιό. Circuit according to claims 1 to 9, characterized in that the load includes the ignition circuit of an ignitron tube. 11. Circuit according to claims 1 to 9, characterized in that the load includes the excitation circuit of a magnetron tube. 1 sheet of drawings © 5551 12.52