DE1011463B - Transistor coincidence circuit - Google Patents

Description

The invention relates to transistor circuits. In particular, it relates to circuits which enable signals to be transmitted in pulse form are given, either to let through or to block, as is the case with electronic ones, among other things Digit calculators is required.

In electronic numeric calculators, usually the entire operation of the facility controlled by so-called time signal pulses, the time sequence of these time signal pulses being the The rhythm of the institution's activity is determined. As part of the circuit to be described below its mode of action depends on the presence of such time signal pulses, it is required to make the assumption that these time-symbol pulses are in another part of the facility are generated and that the timing of the input and switching signals in a precise relationship to the occurrence of the time signal impulses.

In circuits in which hot cathode tubes are used, this in turn is controlled by control circuits which also contain hot cathode tubes is generally called Control circuit uses a push-pull pair of tubes connected to the anodes of the two tubes Provides output pulses that can be used for control purposes, each being the output pulse of one anode, as can be readily seen, the reversal of the output pulse the other anode. It follows that such a, coupled in push-pull circuit A pair of tubes can be used to generate either positive-going control pulses or to deliver negative steering impulses. In contrast to this, a transistor circuit delivers with two switching states only one output pulse, which is normally positive. So if such an output pulse is to be used to control a circuit, it must be possible to use the same either to use as a switching signal that makes the circuit conductive in order to let a pulse through, or as a switching signal that prevents the circuit from becoming conductive and so on prevents the passage of a pulse.

There are already known transistor circuits in which means for establishing a rest potential are provided for each of the electrodes' of the transistor so that the transistor is normally in is in a non-conductive state. By supplying pulses via three different inputs this known circuit the transistor can be controlled into the conductive state, while pulses can be supplied via a fourth input, which the former Transistor coincidence circuit

Applicant:

National Research Development
Corporation, London

Representative: Dipl.-Ing, R. Holzer, patent attorney,
Augsburg, Philippine-Welser-Str. 14th

Claimed priority:
Great Britain 7 April 1954

George Brian Barrie Chaplin, Faringdon,

Berks (Great Britain),
has been named as the inventor

Make input signals ineffective. The output pulses are in this known circuit from Collector circuit derived.

It is known to use the signals supplied to the first three inputs of the circuit to lead conductive switching elements only in one direction, so that they only become effective when they occur at the same time. If one of these signals is absent, those at the other inputs also remain applied signals are ineffective in terms of raising the emitter potential.

This known transistor circuit is relatively insensitive.

In contrast, the invention relates to a highly sensitive control circuit in which even the slightest Voltage increases in the control circuits are sufficient to change the respective other switching state bring about. As a result, the circuit according to the invention is suitable in contrast to the one mentioned above known circuit in a much wider scope than control circuit for electronic numeric calculators and other highly sensitive electronic circuits. This is with the invention Circuit in particular due to the fact that according to the invention in the base circuit of a transistor a damped inductance is arranged.

The inventive e transistor circuit for Delivery of an output signal to the collector

709 586/127

Ϊ Oil 463

electrode: depending on the presence of one Input signal · and a higher-level control signal at the other two electrodes, where each electrode has a certain resting potential and the "first of these four" states are used for the inverse * ZeitzeiehetiimpUils ■ unid the delayed inverse time signal pulse (in addition, the emiHterkreis and the'Base

led wind and. the control signals of a particularly by 5- ^Arrival: prepare input pulse signal,

applied blocking potentials are made ineffective, is consequently initially characterized in that 'in the base circle a damped inductive Load is provided. After another Meirk

üidem the cathode potentials of the diodes, D ₂ UWdItD ₅ * - are raised. As soon as this is the case, the emitter voltage rises due to the input pulse and switches the. Transistor on ,, whereby the ■

times the invention, the base ib collector voltage is raised in the idle state and an off potential held more positive than the emitter potential! output pulse is generated. This is if it is present

Further features and advantages of the invention of a "forward" pulse at the cathode can be found in the example below Diode D ₁ , the voltage of which is consequently raised and thus allows that the Spannuij ^ s invention. In the description, reference is made to the increase due to the input pulse dam. Drawings taken, which show the following: Emitter is communicated. Since there is no § |

Fig. 1 is a circuit diagram, which an execution pulse is present, the potential of the;

example of a transistor circuit according to the invention does not show raised above the emitter potential, and the transistor can switch on as a result. ^: ^

Fig. "2 is a waveform diagram for explaining the 20 The coil L inv base circle by means of a resistance - Figure 1 prior to the R _^2;! .Kritischen or slightly above the ·.

Reference is now made to FIG. The critical damping value is set. If the circuit shown there contains a transistor T. Circuit stops, then it rises; the ■ the emitter of the transistor T is connected to a diode coil L current flowing until after a certain ■ with earth and over a high impedance with a 25 time span, which to a certain extent of the type this ■ negative voltage source connected to the transistor depends, this current would serve V ¹ . Impedance: serves to switch off a rise in the emitter transistor. With the voltage shown during the absence of an input signal circuit, however, the 'time signal pulse' is dearly to be prevented, since such a rise is fed to the emitter base via a diode D ₃ , so that the voltage there is a risk of a "wild" switching of the 30th would result in a positive end of this ■ time signal pulse circuit. The input signal is used to turn off the transistor. The effect will be 'the emitter via' a resistor R ₁ and the coil L is therefore the one. Impedance of the base is fed to a _{capacitor C 1.} The output circuit with reference to transient processes to erimpuls is tapped from the collector electrode, high, whereby the circuit with reference to the; which is made more sensitive to a negative voltage via a resistor. On the other hand, a voltage source of minus 50 volts is connected. In is the base electrode supplied direct current ■ absence of signals is retained, however the same · via the coil L, -. Da ', the resistor ¹ is gearing by means of a catch diode at a voltage of coil L with respect to direct current of the held minus 14VoIt. The base electrode is about The mode of operation of the circuit 'is with ■'. Relation :

a coil L and a parallel resistor 40 to the state II the following:

was i? ₂ via a series capacitor C ₂ and a der via the resistor R ₁ and the capacitance C ₁

The Emitter-plus SOVoIt tries to connect another resistor to a voltage source of incoming input pulse. Normally the voltage will increase, but der'der. Cathode · Base held by means of a diode D ₄ at a voltage from the diode D ₆ supplied "blocking" pulse plus 2 volts at the same time. The control of the circuit 45 raises the base voltage so that the transistor is not 'turned on' by pulse signals which the emitter is switched on. With the Veff shown at III

conditions there is also the "passage" pulse form; however, since that of the cathode of the diode Dg; supplied inverse time signal pulse voltage with ■ 50 reference to the _{inverse time signal pulse voltage supplied to the cathode of the diode D 5} is delayed) 1, the base voltage is increased in time before the "emitter voltage, so that the transistor" ntkÜhA. is switched on. This delayed ■ inverse ■,

electrode via diodes D ₁ and D ₂ and the base electrode via diodes D ₃ , D ₅ and D ₆ . The waveforms of these control signals are shown in Fig. 2, where

Fig. 2a shows the regularly repeating time signal pulses ■ (anode of diode D ₃ ),

Fig. 2b shows the inverse form of the time signal pulses (anode of diode D ₅ ),

Fig. 2c the delayed and shortened version of the 55 character pulse form is also shortened: see above

inverse: time signal pulse form (cathode which ensures that the emitter voltage

Diode D ₂ ) shows

Fig. "2'e shows the possible form of an input pulse consisting of three positive-going individual pulses,

Fig. 2f shows a possible sequence of "pass" pulses (cathode of diode D ₁ ),

Fig. 2g shows a possible combination of »blocking pulses (cathode of diode D ₆ ) and

is set before the "lock" pulse has died away . ■ '■■

In the example shown at IV, the Eina-60 is missing gear pulse. As a result, it follows,! that:" despite the presence of a "pass" pulse and the absence of a "blocking" pulse no-. Output pulse is delivered.

The input circuit, which consists of a WiBOEr ■■ Fig. 2h, the output pulse that is achieved, 65 was R ₁ and a capacitance C ₁ , needs'be; - '

if the other waveforms shown alike- special mention. The capacity leaves the ivy

occur early. ^ output pulse through while making the normal diffe?

The mode of operation of the circuit can vary depending on the DC voltage level between the ::!

Reference to the four possible, in Fig. 2 in the corridor and the emitter play Uasstf ' (* ,,.

individual states shown are explained. In 70 it is assumed that the input pulse from the iii

Claims (8)

1 Oil output of a similar circuit ■ is derived): The current supplied to the emitter is limited by means of the resistor R1 to a suitable value, which is normally around 3 milliamperes. Because this stream - tries to -. To discharge the capacitance C1 during the presence of an input pulse, the capacitance between the pulses must be charged so that each subsequent input pulse can take effect from the same DC voltage level. In order to be able to do this quickly, i.e. so that the pulse repetition frequency is not reduced, the charge "of the capacitance" is ensured by the fact that "the inverse delayed time signal" pulse voltage is fed to the cathode of the diode D2. As a result, between pulses, the level of the cathode of diode D2 is minus 14VoIt, and the input side of capacitance C1 is rapidly lowered to a lower level at the end of each pulse period. Charging the capacitance via diode D2 not only speeds up the process itself, but also ensures that no charge is imposed on the input. The same method is used with respect to the capacitance C2, which is charged again via a diode D5, which is controlled on the cathode side by means of the "inverse time signal pulse waveform. The switching of the transistor to the non-conductive state will occur automatically in the manner described above Since the current through coil L restores itself and pushes the emitter current back to the point at which the transistor turns off, the interruption of the output pulse due to the turn-off of the transistor can, however, be timed by providing the diode D3, the anode of which The transistor, if left to its own devices, will therefore be switched off by the coil L at a point in time which varies from one transistor to the other shortly before this automatic shutdown dies away, so that so the shutdown always occurs at a previously determinable point in time. Since the transistor 45 'is in the process of being switched off by the action of the coil L, only a very low current load is expected of the source for the time signal pulses. It is noted that when a circuit according to the invention is used only as a "pass" circuit, i.e. H. as a circuit which normally does not pass pulses and passes selected signals under the control of pulses, it is not necessary to provide the "inhibit" pulse input via D6. On the other hand, if the circuit is to lock, i. H. if the same should normally let impulses through, but should block certain signals, the "through" input impulse does not need. In the same way, the diode D3 represents a refinement of the circuit and therefore need not necessarily be λ-provided. The circuit is capable of being changed in various modifications. For example, if negative-going control or "switching" pulses are available, they can serve as "pass" pulses when fed to the base, while they can serve as "blocking" pulses when they are sent to the emitter are fed. It is clear that the circuit shown and described can not only be used as a circuit in itself, but that the positive-going output pulses of the collector electrode can also be used as control pulses for other transistor circuits. Vi ΤΈΝ-Τ A »PROVERBS!: - 1. Transistor circuit for supplying an output signal at the collector electrode depending on the presence of an input signal and a higher-level control signal on the other two electrodes, each electrode being supplied with a certain resting potential and the control signals are made ineffective by specially supplied blocking potentials, characterized in that a damped inductive load is provided in the base circuit. 2. Transistor circuit according to claim 1, characterized in that the idle state Base potential is kept more positive than the emitter potential. 3. A transistor circuit according to claim 2, characterized in that the input pulse signals are fed to the emitter circuit in such a way that the emitter potential is more positive than that of the base, but only if at the same time the emitter has additional control pulses via switching elements which are conductive in one direction only (D ₁ , D ₂ ) are supplied. 4. Transistor circuit according to claim 2, characterized in that the input pulse signals are fed to the emitter circuit in such a way that the emitter potential becomes more positive, but that the input pulses become ineffective when the base simultaneously has additional positive pulses via switching elements which are conductive in one direction only (D ₆ ) are fed. 5. Transistor circuit according to one of claims 1 to 4, characterized in that the emitter is connected to ground via a high impedance to a negative potential source and via a switching element which is conductive in only one direction, that an input circuit connected to the emitter is also provided, _{which has switching elements (D 1} , D ₂ ) which are conductive only in one direction and are connected to a control pulse source, and that finally the circuit of the base has a connection (R ₂ , L, C ₂ ) which connects the base to a positive bias voltage source. 6. Transistor circuit according to one of claims 1 to 5, characterized in that the emitter is connected via a high impedance to a negative potential source and via a switching element which is conductive only in one direction to earth, that the circuit also has an input circuit connected to the emitter ( A ₁ , C ₂ ) and a base circuit (R ₂ , L, C ₂ ), via which the base is connected to a positive bias voltage source and via switching elements (D ₃ , D ₅ , D ₆ ) which are conductive in only one direction to a control pulse source is. 7. Transistor circuit according to one of claims 1 to 6, characterized in that only 'in one direction conductive switching elements (D ₂ , D ₃ ) are provided which connect the emitter circuit and the base circuit with time signal control pulse sources. 1 Oil 463 8. Transistor circuit according to one of claims 1 to 7, characterized in that the base is also connected via a switching element (D ₅ ) which is conductive only in one direction to a time signal control pulse source, the pulses of which are directed opposite to the pulses of the first-mentioned time signal pulse source. References considered: U.S. Patent No. 2,670,445. 1 sheet of drawings