Transistor Switching Circuits Research Articles

Quiz Bell Design using NodeMCU ESP8266 for Quiz Contest at IAIN Pontianak

Quiz Buzzer is one of important elements in a quizz contest. In Tadris Matematika Study Program’s Birthday event, one of contest held is quiz contest for High School Student in Kalbar Province. Hereby, author is going to design the buzzer circuit which is able to be used in that quiz contest. This circuit was build by some components, namely push button, buzzer, indicating light, transistor switching circuit for driving the buzzer and indicating light, and a NodeMCU ESP8266 as the system controller. Design of hardware was conducted by referring to literature studies, basic theory, and datasheet. Testing of developed codes was conducted over the Quiz Buzzer Protoyping that is assembled on the breadboard. Testing results showed that the quiz buzzer circuit working properly as needed and the design of 3 teams quiz buzzer.

Development of a compact magnetically expanding plasma source with a strong magnetic field

A compact magnetically expanding plasma source having a strong magnetic field is developed, where a pulsed solenoid current is provided by an insulated gate bipolar transistor switching circuit. The field strength is successfully increased up to ∼6 kG. The 13.56 MHz radio-frequency power with a pulse width of 28 ms and the operating argon pressure are maintained at 600 W and 3 mTorr, respectively. When the magnetic field strength is increased, the plasma density downstream of the source cavity increases due to the inhibition of cross-field diffusion and appears to saturate above ∼3.5 kG, while maintaining a plasma density of 5 × 1012 cm−3 within the source cavity.

Staircase-Voltage Metal–Oxide–Semiconductor Field-Effect Transistor Driver Circuit for Therapeutic Ultrasound

An important component of all ultrasound systems is the high-voltage pulse generator used to excite the transducer. We created a new type of metal–oxide–semiconductor field-effect transistor (MOSFET) switching circuit for therapeutic ultrasound applications, on the basis of the staircase-voltage drive concept. The staircase drive can significantly decrease the harmonics in comparison with the conventional square-wave drive. Since it does not require a resonant circuit to improve the efficiency, the drive frequency can be freely changed and the total size of the drive circuit can be made smaller. Using a diode in series to the drain of each MOSFET, a staircase-voltage driver was created with a relatively simple configuration. The experimental results of operating a prototype driver, as well as the results from circuit simulation, are discussed.

Experimental study of a single tube high RF power amplifier for ICRF heating system

A concept of a single tube high RF power amplifier was developed for ion cyclotron range of frequency (ICRF) plasma heating system. In the concept, a tetrode was used with a grounded cathode and input power to drive a control grid of the tetrode was provided by a switching circuit. As the new amplifier arrangement can eliminate a low power (10 kW level) and an intermediate power (100 kW level) tetrode amplifiers, their high voltage DC (HVDC) power supplies, and control and monitor system for these amplifiers and HVDC power supplies in a conventional high RF power source of the ICRF heating system, this new high RF power source is more flexible on frequency change and more mechanically reliable than the conventional one. A test amplifier composed of the tetrode and a field effect transistor (FET) switching circuit was constructed. The FET switching circuit was so compact that it could be mounted close to the tetrode socket. The maximum output RF power of 8.5 kW was obtained with a plate efficiency of 82% at 70 MHz. The feasibility of the single tube high RF power amplifier was experimentally proved. The plate efficiency of 82% could not be explained by the standard class-C amplification but by high efficiency amplification under assumptions of a flat-topped plate current pattern and double resonance of an output cavity at the fundamental frequency and the third higher harmonic frequency.

A new simplified high radio frequency power amplifier

In order to simplify a present standard high rf power amplifier of ion cyclotron range of frequency plasma heating system, a new amplifier arrangement composed of a tetrode with a grounded cathode and a field effect transistor (FET) switching circuit providing an input rf power is proposed. The FET switching circuit is so small that it can be installed close to the tetrode in one cubicle. It might be called a single tube high rf power amplifier. A test amplifier composed of the tetrode (8F76R) and the FET (2SK-1310) switching circuit is constructed. The maximum output rf power of 8.5 kW was stably obtained at 70 MHz. The feasibility of the single tube high rf power amplifier was experimentally proved.

Implementation of digital IC functions with pass transistor switching circuits

The author implements a modified Karnaugh map minimization procedure for pass transistors. The savings in silicon area depends on the transistor count as well as the interconnect structure. Examples demonstrate that considerable savings in silicon area can be achieved by using pass logic instead of gate logic. The savings amount to an 80% reduction in silicon area for NMOS and 6% reduction for CMOS. This means that more die can be fabricated on a silicon wafer, leading to a reduction in product development costs.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

New approach to the design of thyristor and transistor switching circuits

The paper gives a new approach to the design of power electronic circuits. Time periodic functions of excitation and response are required as input data for the design. A sequence of the linear time-invariant circuits is found on the basis of these data. As a result of the synthesis method new switching structures are obtained. The synthesis method presented can be applied to create new thyristor and transistor arrangements, particularly thyristor compensators.

Formal design procedures for pass transistor switching circuits

Two formal design techniques are presented to realize pass logic networks in NMOS and CMOS technologies. The first technique uses a modified Karnaugh map minimization procedure, which can be effective tool for the design of networks up to five or six variables. For networks involving more than six variables, an algorithmic procedure is developed by modifying the conventional Quine-McCluskey approach. The savings in silicon area depends on the transistor count as well as the interconnect structure. Maximum topograph regularity for an array of pass transistors can be achieved in the intersection of the set of control variables with the set of pass variables in a null set. This allows the pass variables and the control variables to flow at right angles to each other. This requirement may increase the transistor count in the design, hence there is a tradeoff between topological regularity and transistor count. Cells drawn in CMOS and NMOS are compared.

２電極スイッチング・アーク溶接法に関する研究 ＶＩＩ ホットワイヤスイッチングＴＩＧ溶接法におけるワイヤ溶融特性

A new hot wire TIG welding process has been developed to prevent magnetic interaction between TIG arc and hot wire current. In the new process, TIG arc current and hot wire current which are supplied from D.C power source are alternately switched by transistor switching circuit. Arc phenomena, wire heating and melting condition and upper limit of wire melting rate were investigated using this new process for stainless steel plate.The results obtained in this study are as follows.(1) Arc interaction at the time of TIG peak current was preventable and arc interaction at the time of TIG base current was slight when TIG base current was 50 A bellow.(2) Correlation of the hot wire feed rate and wire melting current was obtained in bead on plate deposition without TIG arc.(3) Relation between wire feed rate, deposition rate and wire current was obtained under bead on plate welding. Upper limit of wire melting rate was closely related to hot wire current.

DESIGNING OPTIMUM SNUBBER CIRCUITS OR THE TRANSISTOR BRIDGE CONFIGURATION

ABSTRACT Snubbers are used in power transistor switching circuits to keep the device operation within its Safe Operating Area (SOA) during switching. The conventional series and shunt snubbers are satis -factory in a single transistor circuit. However, these are not satisfactory for a totem pole transistor arrangement. In this paper various snubber circuits are analysed and their effects are discussed. A snubber circuit is developed and tested which is suitable for transistors in bridge configuration. The circuit is thoroughly analysed and design equations are derived for the snubber components.

Selection of Snubbers and Clamps to Optimize the Design of Transistor Switching Converters

In power transistor switching circuits, shunt snubbers (dv/dt limiting capacitors) are often used to reduce the turn-off switching loss or prevent reverse-biased second breakdown. Similarly, series snubbers (di/dt limiting inductors) are used to reduce the turn-on switching loss or prevent forward-biased second breakdown. In both cases energy is stored in the reactive element of the snubber and is dissipated during its discharge. If the circuit includes a transformer, a voltage clamp across the transistor may be needed to absorb the energy trapped in the leakage inductance. The action of these typical snubber and clamp arrangements is analyzed and applied to optimize the design of a flyback converter used as a battery charger.

Principles of d.c. Transistorized ‘Nor’ Gates Design

The main difficulties for designing transistor switching circuits, as transistorized ‘Nor’ gates, are connected with process of optimization several conflicting demands, the combined effect of which cannot always be considered during calculations directly. In this paper the analysis of ‘Nor’ logic gates is formulated on the basis of graphic-analytic method4,5, permitting to take into consideration the total influence of circuitry parameters, variations due to temperature, loading and technology tolerances, etc., in order to obtain the reliable switching mode of operations. It also allows to take into account dynamic and economic requirements for the further optimization, and from this point of view it can be very useful for many transistorized digital circuits including the integrated switching circuits for mass production.

A transistor relay circuit for radiosonde

The audio-modulated radiosonde used in the India Meteorological Department utilises an electro-mechanical relay in its telemetering circuit. A transistor switching circuit which replaces this relay without requiring any modification In the radiosonde is described in this paper.

Modeling and simulation of insulated-gate field-effect transistor switching circuits

A new equivalent circuit for the insulated-gate field-effect transistor (IGFET) is described. This device model is particularly useful for computer-aided analysis of monolithic integrated IGFET switching circuits. The results of computer simulations using the new equivalent circuit are in close agreement with experimental observations. As an example of a practical application, simulation results are shown for an integrated circuit IGFET memory cell.

Study of Transistor Switching Circuit Stability in the Avalanche Region

In the common-emitter transistor switching application, there are occasions in which the collector supply voltage exceeds the transistor sustain voltage. Consequently, the load line could intersect the negative resistance characteristic of the device in the I /sub C/ -V /sub CE/ plane, resulting in a possible unstable or latch-up condition. The purpose of this paper is to study analytically the avalanche region characteristics and their implications for transistor switching applications. The first part is concerned with the derivation of the direct current-voltage relation that, when viewed from the output terminal, represents a negative resistance. The characteristic of this negative resistance depends on the base-emitter circuit condition. The ac terminal behavior is treated in the second part where consideration of the frequency dependence of alpha leads to an equivalent circuit consisting of an inductance in series with a negative resistance. Both elements are nonlinear as well as frequency-dependent. With an external load connected to this nonlinear circuit, a technique of nonlinear analysis is employed to investigate the circuit stability. From this analysis, latch-up and oscillation phenomena in the transistor switching circuit can be predicted. Since the second breakdown involves additional mechanisms besides avalanche multiplication, it is not discussed in this paper.

An analysis of AC controlled push-pull magnetic amplifier with compensating voltage

An equivalent circuit analysis of an ac controlled push-pull magnetic amplifier is performed, which is compensated with a transistor switching circuit [1] in order to overcome the negative feedback action by the gating induced EMF. The modes of the operation of this new push-pull magnetic amplifier circuit are made clear for cases of various degrees of compensation. The theoretical formulas on both the steady-state control characteristics and the transient time constant are derived. Moreover, the steady-state control characteristics and the transient time constant are calculated for several values of compensating voltage. The results obtained show good agreement with the experiments.

Storage and Switching Circuits for an Electronic Telephone System

Sonic wire delay lines are used for the storage functions and transistor switching circuits for the logic functions comprising the common control of this electronic telephone switching system. Because only short-term storage of transient information (identity of the two parties during a telephone conversation) is required, sonic delay lines are uniquely suitable as storage elements. The use of modern high-speed transistors results in simple and reliable saturated-mode switching circuits operating at a clock frequency of 1 Mc/s.

Pushbutton dial mobile radiotelephone an advanced concept in common carrier mobile service

A real need has developed for common-carrier mobile radiotelephone service which can be connected directly into dial telephone exchanges. Many exchanges are now unattended and the mobile subscriber must be able to dial his calls and receive calls in the same manner as with his office or home dial telephone. The transmission of the dialing information from a moving vehicle into the exchange, with the accuracy required to meet telephone standards, has presented an interesting challenge in view of various radio propagation characteristics often experienced, particularly from weak signal or fringe areas. The pushbutton type of dialing described in this paper provides a digital signalling system employing tones of sufficient duration to ride over the numerous signal drop-outs sometimes lasting more than 100 milliseconds. Extensive field experience has proven this approach to be highly reliable and consistent in dialing from a mobile unit. A unique application of counter tubes and transistor switching circuits is employed in the conversion of the tones into dial pulses at the base station terminal. The use of pushbuttons has been found to be very convenient for mobile service. A number of the various features incorporated in mobile dial systems are described in this paper.

On the Application of the Base Charge Concept to the Design of Transistor Switching Circuits

This paper describes a new method of measuring the effective decay time of excess minority carriers in the base of junction transistors, the results of which show an approximately exponential decay with time. The relation between the decay-time constant and the normal and inverse transistor parameters is discussed, and it is shown how the experimental measurements can be directly applied to the design of transistor pulse circuits. Using the Ebers and Moll equivalent circuit for a saturated transistor, an analysis is made of the effect on the charge storage caused by the passage of a collector current when the base connection is open circuit. The case of a transient collector current is also examined, and it is concluded that for typical alloy junction transistors the passage of a collector current plays little part in determining the charge storage. Thus, the storage time with open-circuit base is determined by the initial excess charge, the collector current existing when the transistor enters the active region, and the decay time constant for minority carriers. A simple equivalent circuit for determining the decay of stored charge when a reverse base current is applied is also discussed.

Electronic Control of Some Active Bioelectric Membranes

Special purpose real-time analog computers are used to measure and control nerve membrane or current in a squid axon or a single frog node. Under current control, the membrane has a region of discontinuity and an action potential rather similar to that observed in normal impulse propagation. With control, the current pattern is a continuous function of the potential, and a negative resistance is found in the region of discontinuity for the current-controlled membrane. The membrane's electrical characteristics may therefore be compared with some two-terminal transistor switching circuits.