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In this paper we investigate the multi-stable transistor circuits of which basic operation can be regarded as threshold logic. The sensitivity analysis on the actual circuits is also considered as well as their logical behaviour.
The multi-stable circuits are usually constructed from the flip-flop circuits which have basically two transistors. The transistor, however, can be regarded as a comparator whose output ('0' or '1') depends on whether the input level is higher than a reference (including the insensitive region) or not. Hence, combining it with an adder circuit, each input of which is multiplied by some factor, the circuit operates as a threshold device (Hampel and Winder 1971).
In this paper we investigate these problems and suggest that the network constructed from n threshold devices is useful only as an n-stable circuit. [ABSTRACT FROM AUTHOR]

The paper describes a circuit containing a junction transistor and a F.E.T. which behave as a one-port voltage controlled negative resistance of adjustable magnitude.
One-port negative resistance circuits, being very useful in synthesis of network functions, filter design and the design of regenerative circuits, have been developed by many authors (Waldmann and Beiri 1955, Indiresan 1959, Nagata 1965, Martinelli 1966). In this paper a new voltage controlled negative resistance circuit employing a transistor and a F.E.T. has been proposed which is different from the existing circuits regarding its network topology. The circuit requires no internal bias. As this circuit utilizes one transistor and a F.E.T., the circuit can be readily fabricated as an integrated module. [ABSTRACT FROM AUTHOR]

This paper describes briefly the ideal characteristics required for tripping for faults within the first zone of a distance relay adapted to the protection of a transmission line. The quadrilateral characteristic on an R-X diagram, which is the ideal characteristic, is obtained using a new hybrid comparison technique. This technique possesses the flexibility of conforming to any desired characteristic by a simple change in the selection of current inputs. The relays are described in their block schematic form.
In this paper the first zone distance relay is considered and the desirable shapes of its characteristics are discussed. A new hybrid comparison technique is used to obtain these desirable characteristics. The comparator models are described in their block schematic form. [ABSTRACT FROM AUTHOR]

The expressions previously derived by the author for the resistance parameters of the composite transistors are used to investigate theoretically the open circuit characteristics of the compound configuration consisting of two-point contact type transistors. It is found that the system has, in general, a much smaller current gain, voltage gain, input resistance and higher output resistance. The characteristics are greatly modified when the second-point contact type transistor is replaced by a junction type.
Recently the author, in his paper (Singh 1969), has derived the general expressions for the resistance parameters of the composite transistors in terms of the open circuit parameters of the individual transistor. The characteristics of the compound systems in all the three configurations were, however, not theoretically investigated although these have already been discussed by Suen (1968) in terms of the hybrid parameters. Therefore in this paper the author presents the quantitative analysis of the characteristics of the Darlington configuration on the basis of its resistance parameters. [ABSTRACT FROM AUTHOR]

The design of a monolithic current-controlled current source (CCS) based on the intrinsic matching properties of similar adjacent transistors is described. Experimental and theoretical results are presented and compared. This CCS has been specially tailored for use in a four-quadrant multiplier circuit discussed in a earlier communication (Scholtzhauer and Viswanathan 1972).
This paper describes a current-controlled current source (CCS) designed as an input driving module for a four-quadrant analogue multiplier (Scholtzhauer and Viswanathan 1972). This application requires a broadband, stable and linear unity current-gain block with high output resistance, low input resistance and low input offset voltage, plus a special-purpose second output. This output should be formed as I = I/( + 1), where I is this auxiliary output, I is the main output and is the common-emitter gain of a single transistor matched with the devices in the multiplier circuit. [ABSTRACT FROM AUTHOR]

The paper presents the analysis of a Darlington composite transistor amplifier in the super-alpha configuration. Equations have been developed to study the variations of voltage gain, current gain, power gain and input impedance with load resistance and frequency. Calculations have been made using the IBM 1130 computer for the case of a typical transistor working under typical operating conditions. Graphs representing these variations have been presented and discussed in detail. This Darlington composite transistor amplifier is found to offer some interesting possibilities for applications at low frequencies up to 1 MHz. Simple, although approximate, empirical formulae have been suggested for making ready calculations of voltage gain and power gain in this frequency range in the useful range of load resistances up to 1 kohm in the case of 1 MHz and 10 kohms in the case of 100 kHz. The maximum voltage and power gains obtainable are about 10 with 1 MHz and 1 kohm limitation an 1 about 100 with 100 kHz and 10 kohms limitation. [ABSTRACT FROM AUTHOR]

Previous work by the authors on large-signal transistor characterization and oscillator design is briefly reviewed before introducing the concept of the transistor complex voltage gain/power (A, A, P) space. This is shown to give insight into a systematic approach to the design of harmonic oscillators on the basis of prescribed operating point, power and frequency.
1. Introduction
Transistor oscillators find extensive application to the generation of nearly sinusoidal (i.e. harmonic) waveforms over a wide range of frequency. The design of transistor oscillators at the lower frequencies is typically characterized by well-tried circuits (e.g. Hartley, Colpitts), the use of crystals for frequency definition, and the value of simple feedback theory as a conceptual aid in design. In contrast, at higher frequencies--and especially in the microwave region--the identification of a lumped equivalent circuit becomes increasingly difficult, limiting non-linearities are now to be found more often within the active device, generated power is of greater importance and feedback concepts are increasingly difficult to apply. Thus, for transistor oscillators operating at high frequencies, what is required is a design basis appropriate to the measurement technique and means of device characterization most suited to this range of frequency. The design basis should, moreover, permit the simple consideration of such oscillator properties as the frequency and amplitude of oscillation, output power and load conductance, under a variety of constraints such as the available active device, the type of embedding , the location of the load and the values of the embedding elements. A design basis attempting to satisfy these requirements, and of potential value in microwave transistor oscillator design, is described in this paper. [ABSTRACT FROM AUTHOR]

This paper describes the design of an economical transistorized stimulator suitable for use by students in physiological studies, as well as in research applications. The repetition rate, pulse duration and magnitude of the output pulse are individually selectable by range and by variable fine control within each range. The instrument has been designed with completely indigenous components.
There have been considerable attempts in recent years to build an economical electro-stimulator suitable for demonstration purpose in physiology and biomedical laboratories. The results of Meyer (1967), Bakema and Koopmans (1968) and Dascalov (1969) may be mentioned in this regard. No such solid-state equipment is available with indigenous components in this country as far as the authors are informed. Further, the electrical stimulation of paralysed muscles has been gaining considerable momentum and its importance has been felt in recent years (Vodovnik et al. 1965, Vodovnik et al. 1967, Crochetiere et al. 1967). [ABSTRACT FROM AUTHOR]

Frequency-conversion due to mixing action at the emitter-base diode of a high-frequency micro-alloy diffused-base transistor is considered from theoretical and experimental standpoints.
A comparison is made of the relative contribution to the mixing process of the non-linear diffusion conductance and the non-linear depletion-layer capacitance. It is shown that the effect of parametric conversion resulting from pumping of the emitter capacitance is extremely inefficient and much below the observed values. Conversion gain due to the emitter conductance is dominant and is shown to be in reasonable agreement with the measured gain over a range of frequencies.
In the present paper the mixing action of the emitter-base diode of a high-frequency transistor is treated at u.h.f. The capacitive (parametric) and resistive contribution to the mixing action are separated, the theoretical and experimental results are given and a comparison is made. [ABSTRACT FROM AUTHOR]

For accurate noise measurements the use of valves in preamplifiers has its advantages and disadvantages. Analysis in this paper shows that a combination of the bipolar and unipolar transistors offers a very satisfactory substitute for the valve in low noise preamplifiers for operation over a wide range of source resistances (10 -1 M).
In noise measurements a preamplifier is required between the object under test (B) and a frequency selective main amplifier (C) as shown in fig. 1; (A) and (D) represent a standard noise source and a mean square voltmeter respectively. The preamplifier should provide a reasonable amount of amplification (40 to 60 dB), over a wide frequency band, with noise contribution as low as possible. For the latter reason good quality preamplifiers are using carefully selected types of valves and sometimes the input stage is made of several valves connected in parallel. The use of valves in low noise preamplifiers is of course primarily due to the valves being discovered before the other active devices, but also it is due to the fact that, for valves, the external equivalent current noise source i, in fig. 1, is negligible. The usual noise specification of a valve stage is then given in terms of an equivalent noise resistance R (sometimes denoted as R) which is a convenient quantity related to the external equivalent noise voltage source, e in fig. 1. [ABSTRACT FROM AUTHOR]

A number of methods for realizing different active circuit elements have been provided by different authors. Each new circuit or configuration was the result of the contributing authors' experience and insight. It would be very convenient if all such configurations could be derived as a special case from a general theory, instead of depending on the customary cut-and-try procedure. In this paper the outcome of such a general theory is given; i.e. all of the possible negative resistance configurations which can be obtained by employing two ideal transistors along with some special kinds of resistance networks will be given. [ABSTRACT FROM AUTHOR]

A solid state relay is presented in this paper based on the criteria which must be satisfied for a successful re-synchronization of a synchronous machine onto a system. The sequence of logic decision which such a scheme is expected to make is broadly outlined. The components employed basically consist of semiconductor transistors and diodes. The proposed relay was constructed and elaborately tested on the laboratory micro-machines. The scheme is suitable for use in conjunction with modern automatic control equipments. [ABSTRACT FROM AUTHOR]

The expressions for the current amplification, voltage amplification, input resistance and output resistance of the composite junction transistor in terms of the resistance parameters of the individual transistor in the common base, common emitter and common collector configurations are derived. It is found that the composite arrangement, in general, has (i) a much higher current gain and input resistance, and (ii) smaller voltage gain and output resistance in all the three configurations. The characteristics of the composite system are greatly modified when the second junction transistor is replaced by a point, contact type. This is discussed and practical applications pointed out.
This paper presents the analysis of the characteristics of the composite junction transistors in terms of the resistance parameters of the individual transistor in all the three configurations. The modification of the characteristics when the second junction transistor is replaced by a point contact type is also discussed. [ABSTRACT FROM AUTHOR]

The influence of gradual capture on the cut-off frequency of p-n-p transistors is studied.
The results obtained show that the p-n-p transistor with narrow base in which the lifetime increases in the direction of the hole diffusion may be used at higher frequencies than the p-n-p transistor in which a reverse situation occurs.
The theory of p-n junctions and transistors was given by Shockley (1949). The p-n-p transistors with variable signals have also been considered in later publications (Zawels 1954, Giacoletto 1954, Lo et al. 1956).
Recently, Dolocan has considered the role of gradual capture in p-n junctions with variable signals (1968) and with d.c. signals (1969). It is the purpose of this paper to present an analytic treatment of p-n-p transistors with variable signals by taking into account the gradual distribution of the capture centres' concentration. [ABSTRACT FROM AUTHOR]

In an electrical analog of a tidal channel the simulation of friction by electrical resistance poses a serious problem, since hydraulic friction between two sections depends not only on the discharge but also on the existing water depth, while a normal electrical resistance element is independent of either current flowing through it or of the potential difference across it. in this paper an attempt has been made to develop an analog electronic circuit, using transistors and diodes, the resistance of which varies in the same non-linear fashion as does friction in its prototype. [ABSTRACT FROM AUTHOR]

The field-effect transistor (FET) has a very high input resistance compared with the conventional junction transistor. Unfortunately, however, the transconductance, g, is relatively low in the FET, and its cut-off frequency, f, also is low because of the large input and output capacitances. The FET designed to have high g has inevitably a large input capacitance.
These disadvantages are, however, easily compensated by connecting the FETs so that their input and output capacitances form the shunt elements of constant-k type circuits or m-derived type circuits with the insertion of inductances between each FET. This method makes it possible to increase the degree of freedom in designing the FET and is suited to integrated circuits by the physical simplicity of the structure.
In this paper the design theory is explained first, and this is then found to agree closely with the experimental results. The design gives the ultimate high-frequency limit and the number of FETs to realize the required voltage gain as functions of bias conditions, physical structure and physical parameters of the FET.
The various geometries of 'the travelling-wave field-effect transistor' are investigated to clear their suitability for the integrated circuits. [ABSTRACT FROM AUTHOR]

In order to determine dynamic currents and voltages of a circuitry containing transistors, dynamic transistor characteristics must be known. This paper shows how to derive dynamic transistor characteristics for a charge-controlled transistor model by a synthesis of Ebers and Moll's static and Beaufoy and Sparkes' dynamic transistor relations. Dynamic transistor quantities may then be determined by two methods: one may solve the related system of dynamic circuit equations directly, and another may solve the system of corresponding ' adjoined static ' circuit equations leading to 'adjoined static' quantities from which dynamic quantities may then be computed. Adjoined static quantities are time-dependent quantities which would be observed if all base-charging currents were supplied from wells inside the transistor base, whereas in reality they are supplied by sources outside the base, leading to the observation of corresponding dynamic quantities. The possibility of deriving dynamic from adjoined static quantities follows from the basic assumptions of charge-control theory.
If switching times or, more generally, durations of dynamic transistor processes in terms of base charge only are required, then, given current or voltage control, the respective control quantity being known as a function of time, it is not necessary to formulate and solve the complete system of circuit equations. In the case of current control, one may solve Sparkes' equation, assuming different values for the switching time constant corresponding to the various operating regions. In the case of voltage control, an analogue equation may be solved, derived from a generalization of Sparkes' equation, which obviates the need for regional time constants. Both methods do not lend themselves well to the determination of dynamic transistor currents and voltages generally, except in the active region where base charge and output current are approximately proportional. [ABSTRACT FROM AUTHOR]