DE1025011B - Control device with a semiconductor body with two zones of one conductivity type and an intermediate zone of the opposite conductivity type, with barrier layers between adjacent zones - Google Patents

Description

GERMAN

The invention relates to electrical circuits using semiconductors and in particular on circuits in which transistors with P-N layers that carry a current in both directions ■ pass through, can be used.

It is known that switching operations electronically through the use of vacuum tubes or by gas pipes as a switch. However, all have such electronic Switches have a common disadvantage. An electronic switch can never generate a current run in both directions. The invention is an innovation for such electronic watch holders created, namely in which very = fast working circuits are specified, which in both Directions current-permeable electronic switches included. These switches are based on the properties of transistors with P-N layers.

The theoretical basics of transistors with a P-N layer are, for example, in the book by S hockley, "Electrons and Holes in Semiconductors", Verlag D. van Nostrand Co., 1950, included.

A transistor with a P-N layer contains a semiconductor body ζ. B. of germanium or silicon, in which adjacent areas of opposite conductivity type are present. Lines are connected to these areas by means of an ohmic and no rectifying effect Contacts (in contrast to the contacts with rectifying effect in the so-called point contrast transistor) connected. Nonlinear phenomena occur within the semiconducting body, whereby the contact areas between the various areas mentioned are the seat of these phenomena are. Among the basic forms of transistors primarily used for the invention are to be, the semiconductor body contains three successive zones of each alternating Conductivity type, because it consists of P-N-P transistors, in which two P-regions are separated by an intermediate N-region are separated, or from N-P-N ~ transistors, in which a P-region lies between two N areas.

The experiments carried out by the inventor have shown that a reversal of the current direction in a control circuit between the central zone and an end zone of a P-N-P transistor or an N-P-N transistor causes an opening or closing of a consumer circuit between the two end zones. The reversal of the direction of current in the control circuit affects the resistance which the Has transistor in the consumer circuit between the two end zones. This resistance changes from a very high to a very low value control device

with a semiconductor body

with two zones of one line type

and an intermediate zone

of the opposite conductivity type,

with barriers between each other

adjacent zones

Applicant;

Radio Corporation of America,
New York, NY (V. St. A.)

Representative: Dr.-Ing. E. Sommerfeld, patent attorney,
Munich 23, Dunantstr. 6th

Claimed priority:
V. St. v. America of September 9, 1952

George Clifford Sziklai, Princeton, NJ (V. St. Α.),
has been named as the inventor

or the other way around. Furthermore, it was found in these tests that if the current direction in the control circuit a closure of the consumer circuit causes the current in the consumer circuit in both directions can flow. The direction of current in the consumer circuit depends on the sign of the voltage between the two end zones.

These phenomena are in the circuit according to the invention to provide an electronic Control device with a semiconductor has been used, with a control voltage applied to a Control electrode of this semiconductor body is located, a current control of a consumer circuit feeding Power source allowed. In this circuit, the semiconductor body is equipped with two equivalent electrodes, and the consumer circuit lies between these two electrodes. An important quality This electronic switching arrangement consists in the controlled current flowing through the transistor switch flows either in one direction or in both directions, depending on the consumer group this requires.

In an embodiment of the invention in which the consumer circuit contains a choke coil, use is made of the property mentioned

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made an electronic circuit arrangement to be negative with respect to the grounded transmitting electrode 21

create which as a simple and economical one. The collector electrode 25 is grounded to the

Power sawtooth generator is used. Transmitter electrode over a load 29 and over a

A major work of the invention is creating voltage source 28 connected to either one

a simple electronic circuit, the 5 direct current source, z. B. a battery, or a

Currents in both directions. AC power source, as shown in Fig. 1, be

Another purpose of the invention is a circuit arrangement. The base electrode 23 becomes a circuit

to create voltages in which semiconductors serving as switches voltage pulses 40 of positive polarity

used for both directions of current passage opposite to the grounded transmitting electrode 21,

will. io being the voltage of these pulses greater than that

An additional purpose of the invention is to sheep bias the base electrode. This tension

A circuit with a PN layer transpulse comes from the input terminals A and Ä

sistor as a switch for both current directions. via a capacitor 37 to the base electrode.

Another purpose of the invention is the manufacture - in the absence of a positive switching pulse flows development of a simple sawtooth generator below 15 the controlled current by means of the forward

Use of a P-N layer transistor as the bias of the base electrode 23 in the direction of the switch

for both current directions. in such a direction that a pathogen oozes over

Fig. 1 is a circuit diagram showing in general the load 29 and across the transmitting electrode, ode as well

Form represents an embodiment of the invention that closes the collector electrode in transistor 10, in which the current flow through a consumer 20 if, however, a positive pulse 40 of such

is switched by means of a P-N layer transistor; Size occurs that the current direction between the

Fig. 1 a shows the dependency of the consumer base electrode and the transmission electrode vice versa

Current from the control current for a circuit with one becomes the current path between the transmitting electrode

symmetrical P-N Schidhttranaistor, in which one and the collector electrode opened, and the Be-S control circuit between the base electrode and the transmission load circuit is for the duration of this switching pulse

electrode and a controlled circuit or load «- de-energized.

circle between the transmitting electrode and the collector In Fig. 1 there is an alternating current source in the Beelectrode of the transistor is switched; load circuit shown, however, the circuit Fig. 2 is a circuit of another embodiment, also readily on the supply of the load form of the invention, in which two P-N circuits are switched over with direct current. The sub-layer transistors to accomplish the switching search of the behavior of the switching when replacing the Control of the current in the load uses AC power source 28 by a DC power source will; can even for a better understanding of the effect Fig. 3 is a circuit diagram of an additional embodiment of the circuit. First of all, it is a suggestion form of the invention, in which a power saw 35 assumed that the AC power source 28 by a tooth is generated, and battery may be replaced, the negative terminal of which is on Fig. 4 is a representation of the currents and that of the grounded transmitter electrode. As long as then Voltages in the circuit according to FIG. 3. no positive switching pulses occur, the flows 1 shows a circuit arrangement, current in the load circuit from the transmitting electrode 21 in which a P-N layer transistor 10 for the control 40 through the battery and the load 29 for the collector an alternating current in a load uses electrode 25. If a positive switching pulse between which represent the transmitting electrode and the base electrode by a load resistor 29 is. occurs and the current direction in the control circuit changes Transistor 10 can, as shown, a P-N-P- reverses, so the load circuit is opened, and it Be a transistor and thus a semiconductor body, 45 therefore flows during the duration of this positive Imz. B. a germanium body, in which pulses no current through the load, two P-regions 11 and 15 by an N-region 13 of - It is now assumed that the instead of the are separated from each other, these three areas AC power source 28 entered battery the umgesich touch each other. So-called electrical reversed polarity may have, so that its positive Threshold, as it is in the above-mentioned book of 50 clamp on the grounded transmitter electrode. SOS hock ley are mentioned, there is no positive switching pulse at the interfaces for a long time 17 and 19 between the different areas. then the electricity (when considering the classic The electrodes 21, 23 and 25, which are in the direction of current from the collector electrode 25 through offer 11th, 13th and 15 rest, make ohmic, d. H. the load and the battery to the transmitting electrode 21. non-rectifying contacts with these areas 55 When a positive switching pulse occurs in the here. As usual with transistors, the electrodes are reversed and the load circuit is opened, so that in 21, 23 and 25 as the transmitter electrode, the base electrode again no current for the duration of the pulse trade and the collector electrode. flows.

However, with regard to the two possible 60 When observing this behavior, the load current directions in the load circle the designation circle can be used for both direct voltage directions of the electrode 21 as a transmitting electrode and the designation the mode of operation of the circuit according to FIG of the electrode 25 as a collector electrode willing to be an alternating current source in the load arbitrary and should not be easily understood as a limitation of the circle. During the positive Halb function of these electrodes. 65 waves of the AC voltage source 28 behaves In the arrangement according to FIG. 1, the transmission element is namely the circuit according to FIG. 1 as well as with trode 21 directly earthed. The base electrode 23 of a DC voltage source of one polarity in is via a resistor 26 to a voltage load circuit, while the negative voltage source, z. B. a battery 27, the polarity of the half-wave the circuit behaves in the same way as in Battery is chosen so that the base electrode 23 70 of a DC voltage source of the reverse polar

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did in the load circle. If there is an alternating current source in the load circuit, so long as this load circuit by a bias acting in the forward direction between the Base electrode 23 and the transmitting electrode is closed, the load circuit alternating with currents flows through both directions, so that an alternating current flows in the load 29.

It is easy to see that a so-called symmetric is used for the circuit according to FIG. 1 P-N-layer transistors recommends, d. H. the usage of a transistor, in which the relationship between the control current and the Load current for one direction of the load current is practically symmetrical to this relationship for is the other direction of the load current. However, not all P-N layer transistors have this symmetry, mainly due to the manufacturing process used in their manufacture. Some Own transistors for. unites the current in one direction between the outer areas greater resistance for certain values of the bias voltage than for the other current direction for equivalent values Tension between the outer areas.

While the presence or absence of this symmetry depends on many factors, it does take the inventors suggest that if the resistivity of the two outer zones is approximately equal and when the two layers 17 and 19 are symmetrical, i. H. are of the same size, the currents are largely the same turn out to be the transistor as a transistor symmetrical kind.

Sufficiently symmetrical characteristics of a PNP transistor are shown in Fig. 1 a, which illustrate the relationship between the control current and the load current for transistors, the current of the control circuit, i.e. the current between the base electrode and the transmitting electrode as well as in Fig. 1 as Control current is referred to and the current between the transmitter electrode and the collector electrode as the load current. The control current i _b is plotted along the horizontal axis, the positive semiaxis corresponding to the classic direction of current flow into the base electrode and the negative semiaxis to the exit of the current from the base electrode. Furthermore, in FIG. 1 a, the load current i _ec on the upper semiaxis corresponds to the entry of the current into the collector electrode and the negative semiaxis to the exit of the current from the collector electrode.

The characteristic curve 30 shows the course of the load current as a function of the control current when the collector electrode positive, namely constant positive to the transmitting electrode is biased, while the characteristic 31 shows the load current as a function of the control current when the collector is also strongly negative opposite the transmitter electrode.

It can be seen that when the control current flows out of the base electrode (i.e. when in a circle between the base electrode and the transmitting electrode have a bias voltage effective in the forward direction lies), the load current increases with increasing control current and that these current ratios the same are independent of whether by the bias voltage between the transmitting electrode and the Collector electrode the current direction is influenced so that current flows into the collector electrode or that load current flows out of the collector electrode. You can also see that the load current becomes vanishingly small or zero in both directions for all values of the control current that flow into the base electrode (i.e. when in the circle between the base electrode and the sending electrode a so-called reverse voltage is effective).

It should be noted that in some applications of the circuit of FIG. 1, namely when the symmetry the AC supply of the load is not critical or if the load is only excited with direct current is to be, the transistor 10 does not need to be symmetrical in the sense of FIG. 1 a. One can in In these cases, if desired, even choose a highly asymmetrical transistor as the switch. if however the load current. must have the same size in both directions, be strictly symmetrical instead of the circuit in FIG. 1, the circuit in FIG. 2 can also be used.

The embodiment according to FIG. 2 is of particular advantage when the transistors for control of alternating currents. If you choose the circuit so that the current path between the transmitting electrode and the collector electrode of both transistors 40 and 60 in parallel, but in reverse Direction runs and if both transistors are of the same type and the same asymmetry ^ with regard to their characteristics between the control current and the load current, one can also use a symmetrical transistor with such asymmetrical transistors Create a load circuit for both directions of current.

The transistor 40 in Fig. 2 is a P-N-P transistor with two P-regions 41 and 45 between which an N-area43 lies, and with thresholds or barriers between the individual areas at the separating surfaces 47 and 49. The sending electrode, the base electrode and the collector electrode 51, 53 and 55 are in ohmic contact with the corresponding zones 41, 43 without rectifying properties and 45.

The transmitting electrode 51 is directly connected to earth, while the base electrode 53 has a resistor 79 and a bias source, e.g. B. a battery 77 is connected to the grounded transmitting electrode. The polarity of this battery is chosen so that the base electrode 53 is in the so-called reverse Direction is biased, d. H. comes to a positive potential compared to the transmitter electrode. The collector electrode 55 is about a load, which is indicated by the resistor 83 and about a Voltage source 81 is connected to the grounded transmitting electrode 51. It is assumed that the characteristic of the transistor 40 may run symmetrically in the sense discussed above and that the current in the classical direction of current in the outer circle from the collector electrode to the transmitter electrode.

The circuit according to FIG. 2 also contains a second transistor 60 which, with regard to its type and its asymmetry corresponds to transistor 40. Thus, the transistor 60 has two P-zones 61 and 65, between which an N-zone 63 lies, has two intermediate layers 67 and 69 and a collector electrode 71, a base electrode 73 and a transmitting electrode 75, which have an ohmic and no rectifying effect having contact with zones 61, 63 and 65. The asymmetry of the control current and the load current of transistor 60 is such that the current in the external load circuit of the collector electrode flows to the transmitter electrode.

The collector 71 of the transistor 60 is connected to the grounded transmitting electrode 51 of the transistor 40

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bound, while the transmitting electrode55 of the transistor with the areas 111, 113 and 115 and are in the 60 connected to the collector 55 of the transistor 40 as the transmitting electrode, the base electrode that is. The base electrode 73 of the transistor 60 is and denotes the collector electrode, connected to the base electrode 53 of the transistor 40. The transmit electrode 121 is grounded, and it stands by

and the base electrode 73 is thus in the so-called 5 a control circuit with a resistor 126 and called the reverse direction, ie positively biased against a voltage source, for example a battery, via the earthed collector 71. The 127 between the base electrode 123 and the transmission control circuit between the base electrode and the transmission electrode 121. The connections of the battery are so geelectrode of the transistor 40 (and thus also selects that the base electrode in the forward direction, control circuit between the The base electrode and the coil (ie negative in relation to the transmission electrode, the pre-supply electrode of the transistor 60) are voltage-voltage. A choke coil 131, whose distributed voltage source 87 of negative polarity is indicated by the input capacitance by a capacitor terminal B and B ' shown in dotted lines via a capacitor 85 puller 133, is connected in series with a voltage source (namely the charged capacitor). In the pause between these negative voltage sator 129) between the collector electrode 125 and impulses, the current direction in the two control and the grounded transmitting electrode 121 are circulating because of the reversed bias voltage in such a way Zones of both are connected via a resistor 135 to which is blocked by a transistor and the load 83 so-plus sign indicated positive voltage source, with currentless. Remains. If, however, a pulse ao can also be used to connect the bias voltage in the two control circuits to a negative voltage source 87. Periodically recurring chip wounds and the current direction in these voltage pulses 140 are reversed by a control circuit connected to terminals S , a current flows in the pulse source connected to S ' via the two parallel branches between the capacitor 137 to the control circuit between the base Sending electrode and the collector electrode of the two 25 electrode and the sending electrode supplied. Transistors, and for the duration of the impulses, the curve of the current flowing through the choke coil load 83 with an alternating current is denoted by i _L , while the current flows. During this pulse duration, the positive voltage on this choke coil is designated by e _L. be tive voltage half-waves of the voltage source 81. The operation of the arrangement according to Fig. 3 to a bias in the sense of the flow passage 30 by using the Fig. 4 illustrates, through the load circuit from the transmitting electrode for the time J ₁ the current direction in the control collector electrode of a Transistor and in the sense of a circuit between the base electrode and the transmission of the current blocking for the other transistor, elect ■ de as a result of the acting in the forward direction while within the negative half-waves of the original voltage between the base electrode 123 and vice versa is present the load 35 of the transmitter electrode 121 in such a way that the load 83 is a symmetrical, undistorted alternating current, since the circuit is closed over the transmitter electrode and the collector electrode for the illustrated type of parallel connection of the electrode. Because of the polarity of the two current paths between the transmitter electrode and the voltage on the capacitor 129 flow t therefore by which the collector electrode the ratios in the whole choke coil are a current in the direction from the colsymmetric. 4.0 lektorelectrode to the transmitter electrode, which is in the coil It should be noted that Fig. 2 builds up a magnetic field in the control current. If this circuit shows a circling direction of the bias voltage (namely has negligible ohmic resistance, a bias voltage in the so-called reverse direction of the current i _{L will} increase linearly up to the time i ₂ , in the direction), which is suitable for circuits in which a pulse 140 fed to the control circuit to which the circuit for the controlled current or load 45 is supplied, so that the current direction in this flow around must normally be open while it reverses. The load circuit between the Sendeelek-Fig.l in the control circuit shows a bias voltage and the collector electrode is thereby opened (namely a pre-opening acting in the forward direction, and the voltage stored in the choke coil 131) for circuits in which the circuit for energy begins to oscillate in the capacities load current must normally be closed. 50 city 133 to unload into it.

So if in Fig. 1 the connections of the battery 27 If the width of the pulses 140 is equal to half

are interchanged, the load circuit of normal duration of the visual oscillation period of this mode of oscillation is open and is made by suitable negative switching process, the pulse disappears closed pulses. Likewise, namely, the coil voltage E _L each have a mally closed circuit for the load 83 half an oscillation period is in Fig. 2, when the i at the time. "After the current i _L and its AbAnschlüsse be reversed to the battery 77 is a normal 55 line, have gone through. To this established, and this circuit can be opened by suitable timing so the positive switching impulses acting in the forward direction. Voltage between the base electrode and the transmitter

Fig. 3 shows an application example in which the electrode is restored in the control circuit and the 60 load circuit of the ability of the transistors shown is thus closed again. The current switches on a current for both current directions between the transmitter electrode and the collector electrode, to create a simple and reliable current runs in the direction used by the transmitter-class current sawtooth generator to the collector electrode, since the choke coil is 131. The transistor 110 in FIG. 3 can emit a PNP energy to the capacitor 129, being a transistor, as FIG. 3 shows and having 65, the current decreases linearly over time until an N region at time t _i 113 a current equilibrium is reached between two P-regions 111. From now on and 115, the separation surfaces between these regions, the process being repeated in the described offer, being denoted by 117 and 119. The elec- trical way, since the voltage source 129 a timed trode 121, 123 and 125 are in ohmic, linearly increasing current to the choke coil 131 does not provide any rectifier properties, contact 70 until at time t ₅ a new pulse 140 den

Load circuit opens, etc. Since the voltage on electrode 123 is positive compared to electrodes 121 and 125 must be in order to make the transistor conductive, it is advantageous to change the polarity of the To reverse the voltage source (i.e., ground its negative pole) instead of the circuit shown in FIG to be used when the amplitude of the control pulses 140 is to be kept small.

The arrangement according to FIG. 3 thus represents a very high quality arrangement for generating sawtooth currents because the energy of the charged capacitor, which during part of the working period is stored in the choke coil, during a later part of the working period to the capacitor is returned. When the load circuit has no ohmic resistance at all If the power saw tooth were to be produced, there would be no external energy source at all, with the exception of that the one required for the switching pulses.

However, since there is always a certain ohmic resistance in the load circuit, in Certain energy losses occur in this circle, and a smaller one always flows to cover these losses Current through resistor 135.

The circuit of Fig. 3 is largely applicable to cathode ray tubes with electromagnetic deflection. So z. B. the circuit of FIG. 3 can be used for the horizontal deflection in a television receiver, the pulses 140 representing the horizontal synchronizing pulses which occur at the output terminals of the so-called pulse separator. This isolating stage can thus be connected to the terminals S and S ' , and the coil 131 is then the line deflection coil of the picture display tube.

It should be noted that the control circuit between the middle zone and any of the two outer zones of the transistor can be connected. So if for example the electrode on the one outer zone of a symmetrical transistor arbitrarily as a transmitting electrode and the electrode is accordingly designated as the collector electrode on the other outer zone, the choice is yours between the control circuit between the base electrode and the transmitter electrode or between the base electrode and the KoI-lektorelectrode essentially arbitrary. Furthermore, if an unbalanced transistor is used the control circuit between the base electrode and the transmitting electrode or between the base electrode and the collector electrode can be placed, depending on the needs of the individual case.

It should also be emphasized that instead of the P-N-P transistors in the exemplary embodiments described N-P-N transistors can also be used. With suitable polarity reversal for the biases and the control pulses, all the control processes described can also be carried out with N-P-N transistors achieve.

It should also be noted that in practicing the invention, the control signals and the Stress can take different forms. For example, the control signals can be sinusoidal or not be sinusoidal or consist of periodic or non-periodic pulse trains or also have a different shape, depending on the particular control process to be carried out. For example, if a continuously variable control signal is used, it can be seen from Fig. 1 a that the output signal would also change continuously. The load itself can also be borne by the user, for example a lamp, a radiator or a deflection coil, but it can also only be represent the input circuit of a preliminary stage of a controlled electronic system or can finally be a different type of control device depending on the desired consumer.

Claims (14)

Claims-. 1. Control circuit with a semiconductor body with two zones of one conduction type and one intermediate zone of the opposite conductivity type, with barrier layers between each other adjacent zones, characterized in that the semiconductor is an alternating current valve, that a consumer branch lies between the two outer zones, that these zones are so-called equivalent electrodes, d. H. are of the same conductivity type and size and that the relationship between the flow from these outer zones into the middle zone Current is the same as a function of the bias against this latter zone and that a power source is located between the outer zones, which an alternating current through the consumer branch and caused by the semiconductor between the outer zones. 2. Control circuit according to claim 1, characterized in that the control electrode is biased is. 3. Control circuit according to claim 2, characterized in that the control voltage of the constant Bias of the control electrode is superimposed to the resistance that the semiconductor body in the consumer group represents to influence. 4. Control circuit according to claim 3, characterized in that the control circuit has a Contains resistor in series with a bias voltage source and that this resistor is connected between the bias voltage source and the control electrode, the one input terminal for the control voltage is also connected to this control electrode. 5. Control circuit according to one of the preceding claims, characterized in that the Control voltage is a continuously variable voltage. 6. Control circuit according to one of claims 1 to 5, characterized in that the control voltage is formed by a pulse through which the resistance, which the semiconductor body in the consumer group, brought from one value to a different value will. 7. Control circuit according to claim 6, characterized in that the two different Values of the resistance of the current-permeable state and the current-impermeable state of the semiconductor body correspond. 8. Control circuit according to one of the preceding claims, characterized by a second Semiconductor body with two equivalent electrodes and a control electrode, which are all three correspond to the electrodes of the first-mentioned semiconductor body and which correspond to the electrodes of the first-mentioned semiconductor body are connected in such a way that the asymmetries of the two semiconductor bodies in the two with 709 907/133 reversed current direction, parallel circles are effective. 9. Control circuit according to one of the preceding claims, characterized in that the consumer circuit contains a power source connected in series with the consumer. 10. Control circuit according to claim 7, characterized in that the consumer circuit has a oscillating circuit and a DC voltage source, which contains a current in the oscillatory circuit and causes in the semiconductor in one direction, and that the Control voltage from periodically recurring, the semiconductor body in a non-conductive state offsetting switching pulses of a duration approximately equal to half the natural oscillation period of the oscillatable circuit. 11. Control circuit according to claim 10, characterized in that the oscillatable Connection to one of the two equivalent electrodes directly and also to the other of these equivalent electrodes is connected via the direct current source. 12. Control circuit according to claim 11, characterized in that the positive terminal of the Direct voltage source connected directly to the other of the two equivalent electrodes and its negative terminal via the oscillatory circuit to the first of the equivalent Electrodes. 13. Control circuit according to claim 10, characterized in that the vibratable Circuit consists of a coil with distributed capacitance, so that a sawtooth current in this coil arises. 14. Control circuit according to claim 2, characterized in that the semiconductor body is a P-N-P semiconductor and that in its middle zone a positive voltage with respect to both outer zones. Considered publications:
U.S. Patent No. 2,594,449;
Belgian Patent No. 498,396;
Journal: Proceedings of the IRE, June 1953, pp. 720 to 722. 1 sheet of drawings © 709 907/133 2.58