DE1061890B - Transistor circuit for symmetrical control of alternating current - Google Patents

Description

GERMAN

KL.21d ² 42/02

INTERNAT. KL. H 02 j

PATENT OFFICE

S 49163 VIIIb / 21d ²

REGISTRATION DAYi JUNE 22, 1956

NOTICE LOGIN AND ISSUE OF THE EDITORIAL: JULY 23, 1959

The invention relates to a transistor circuit for the symmetrical control of alternating current. It is known per se, for the purpose of controlling alternating currents, transistors have symmetrical properties to give in relation to the reverse voltage or the current gain, however, have the known Transistors that have at least approximately symmetrical properties with regard to their reverse voltage have, d. H. where the reverse voltage between the emitter base and collector base is the same is, a very different current gain in both directions. This is because the Barrier layers of the collector and emitter are of the same type with regard to the alloy, but that the area of the emitter to achieve a particularly favorable current gain is much smaller , is made as that of the collector. On the other hand, in the case of transistors with the same barrier layers the current amplification factor, which is the same in both directions, is only a fraction of the amount the aforementioned version.

Circuits with two asymmetrical transistors have therefore already been proposed, in which the two transistors are connected in series and each transistor has its own Control transformer has or a single control transformer with center tap is provided. There have also been proposed circuits with two transistors connected in opposition in parallel each transistor is preceded by a rectifier and each transistor has its own control transformer assigned. In both circuits, the threshold values of the barrier layers add up, so that a reduction in efficiency is the result.

Avoiding this disadvantage while at the same time reducing the necessary technical effort is the object of the invention. The solution for the transistor circuit for symmetrical control of alternating current using two, in particular asymmetrical, transistors according to the invention is that in each case the base of a transistor alternately with the not to the controlling AC circuit connected to the same type of external electrode of the other transistor and a common control transformer is arranged between the bases of the two transistors is. In the case of transistors, both of the p-n-p type and of the n-p-n type can be advantageous the base of one transistor must be connected to the emitter of the other transistor. To control the AC circuit is the primary circuit of the control transformer 'preferably a rectangular AC control voltage supplied to a transistor circuit for the symmetrical control of alternating current

Applicant:

Siemens-Schuckertwerke

Corporation,

Berlin and Erlangen,

Erlangen, Werner-von-Siemens-Str. 50

Dr.-Ing. Georg Sichling, Erlangen, has been named as the inventor

particularly effective control of the alternating current circuit allows.

In Fig. 1, the new circuit is in connection with an AC circuit to be controlled on hand an embodiment shown.

With 1 there is an alternator, with 2 a control transformer and with 3 and 4 the two, in particular denotes asymmetrical transistors. In the exemplary embodiment here are transistors provided by the p-n-p type, in which the emitters marked with an arrow alternate are connected to the bases in the manner shown. 5 represents one in the AC circuit Consumer that is to be controlled. The two transistors 3 and 4 can be in a common vacuum-tight housing 6 shown in dashed lines so that only the connections for the base and outer electrodes of the transistors (in the case shown, the collectors) this are brought out.

The control of the alternating current takes place depending on the mutual polarity of the Collector of both transistors lying mains AC voltage and the control AC voltage, because of the known mode of operation of the transistors, a current flow through both transistors, namely over Collector — base of one, and emitter — collector of the other transistor, is only possible if at the same time at the collector-base of one transistor and at the base-collector of the other transistor there is a potential of one and the same polarity.

The possible current profiles are shown in FIGS. 2 a to 2 d for all possible polarity ratios.

909 578/176

from the control voltage to the mains AC voltage shown. From this it follows that only in the case of the polarity relationships according to FIGS. 2 a and 2 d Current flow. by the two transistors in the dashed line in the direction shown in the drawing, in all other cases the alternating current circuit, on the other hand Is blocked. ■

When using transistors of the npn type, what has been said above applies in a correspondingly modified manner. ^:: '

Claims (3)

Patent claims: 1. Trahsistor circuit for symmetrical control of alternating current using two Transistors, characterized in that in each case 'the base of one transistor is not connected to the the same type of external electrode of the other connected to the alternating current circuit to be controlled Transistor connected and between the bases of the two. Transistors share a common control transformer is arranged. 2. Transistor circuit according to claim 1, characterized in that the control transformer supplied control AC voltage is rectangular. 3. Transistor circuit according to claim 1, characterized in that the two transistors are housed in a common vacuum-tight housing, from which only the connections for die \ Bäsis- and only two external electrodes of the same type of the two transistors are led out. ■;. · ■■. 1 sheet of drawings «909 578/176 7.59