The operational amplifier (also known as Op-Amp) is a multi-terminal direct coupled high gain amplifier which consisting of one or more differential amplifiers and a level transistor and an output.The Op-Amp is a versatile device which can be used to amplify both DC and AC signals and these are mainly designed for performing mathematical operations like addition, subtraction, multiplication etc.Block Diagram of Operational AmplifierInput Stage − The input stage is the dual input, balanced output differential amplifier. This stage provides most of the voltage gain and introduces the input resistance of operational amplifier.Intermediate Stage − This stage is dual input, ... Read More

A Metal Oxide Semiconductor Field Effect Transistor (MOSFET) has four terminals − Source (S), Gate (G), Drain (D), Body (B). It is a semiconductor device which is used for switching and amplification applications in electronic circuits. In general, the body terminal is connected with the source thus forming a three terminal device just like an FET.The MOSFET is a voltage controlled device. Since its operation depends upon the flow of majority carriers only, hence MOSFET is a unipolar device.In other words, An FET that can be operated in the enhancement mode is known as MOSFET.Why the Name MOSFET? The gate ... Read More

An operational amplifier is a three-terminal device consisting of two high impedance input terminals, one is called the inverting input denoted by a negative sign and the other is the non-inverting input denoted with a positive sign. The third terminal is the output of the Op-Amp.Inverting Operational AmplifierIn the inverting operational amplifier circuit, the signal is applied at the inverting input and the non-inverting input is connected to the ground. In this type of amplifier, the output is 180⁰ out of phase to the input, i.e. when positive signal is applied to circuit, the output of the circuit will be ... Read More

The Insulated Gate Bipolar Transistor (IGBT) is a semiconductor device having three terminals – Gate (G), Emitter (E), and Collector (C). IGBT has been developed by combining the best qualities of both BJT and Power MOSFET. Hence, an IGBT exhibits high input impedance as a PMOSFET and has low ON-state power losses like a BJT.The IGBT is also free from the second breakdown problem that present in the BJT.IGBT is also known as Insulated Gate Transistor (IGT), Metal Oxide Insulated Gate Transistor (MOSIGT), Conductively Modulated Field Effect Transistor (COMFET) or Gain Modulated FET (GEMFET).Basic Structure and Schematic Symbol of IGBTThe ... Read More

Basically a transistor is nothing but two pn-junctions connected back to back. By examining both the junctions (Emitter-Base junction and Collector-Base junction) with the help of a digital multimeter, we can comment on the functionality of the transistor.The test of the transistor is based on the principle of pn-junction biasing, i.e., when a forward bias is applied to the pn-junction (by connecting positive terminal to the p-region and negative terminal to the n-region), the junction allows current to through it. When the reverse bias applied to the junction, it behaves as an open circuit.NPN Transistors are widely used. We can ... Read More

Full Wave Rectifier is a diode circuit which is used to transform the complete cycle of Alternating Voltage (AC Supply) to Direct Voltage (DC Supply).In full wave rectification, current flows through the load in the same direction for the complete cycle of input AC Supply.Types of Full Wave RectifiersCentre Tap Full Wave RectifierFull Wave Bridge RectifierCentre Tap Full Wave RectifierThe circuit of centre tap full wave rectifier consists of following main components −Two DiodesA centre-tapped transformerA load resistanceWorking of Centre – Tap FWR CircuitPositive Half CycleDuring the positive half cycle of input AC voltage, the end A of secondary winding ... Read More

The Enhancement Mode Metal Oxide Semiconductor Field Effect Transistor (EMOSFET) is a three-terminal Device viz. Source (S), Gate (G) and Drain (D). The EMOSFET is a voltage controlled device.The EMOSFET can be operated in the enhancement mode only. The EMOSFET has no physical channel from source to drain since the substrate extends completely to the SiO2 layer.By the application of gate–source voltage (VGS) of proper magnitude and polarity the device can be made operating. The use of VGS induces an n-channel just below the gate terminal and this made the device operating.The minimum value of VGS of proper polarity that ... Read More

Digital electronics is branch of electronics which deals with digital signals to accomplish the tasks. The digital signals are the signals which are represented using the binary language, i.e., 0’s and 1’s.The digital circuits are implemented using logic gates like AND, OR, NOT, NAND, NOR, XOR and XNOR which can perform logical operations.Digital Circuit DefinitionA circuit implemented using a number of logic gate and takes the input in the binary form (0’s and 1’s) is called as Digital Circuit.Types of Digital CircuitsCombinational Digital CircuitsSequential Digital CircuitsDigital Logic GatesA logic gate is an electronic component that is implemented using a Boolean ... Read More

A diac is a two-terminal, three-layer, bidirectional device which can be switched from OFF state to ON state for both positive and negative polarity of the supply voltage.Constructional Details of the DiacThe basic structure of a Diac is similar to a BJT transistor. The only difference is that there is no base terminal in case of Diac.The terminals of the diac are taken from the two p-regions of silicon that are separated by an n-region. The concentrations are identical in all layers to give the device symmetrical properties.V – Characteristics of DiacFrom I-V Characteristics of a Diac, for the applied ... Read More

In practice, a rectifier is used to produce pure DC supply in electronic circuits. But the output of a rectifier is not pure DC, it has pulsations, i.e., it contains AC and DC components. The AC component is undesirable and must be removed. For this, a filter circuit is used."A Filter Circuit is a circuit which removes the ac component from the output of rectifier and produces the pure dc output across the load."The filter circuit should be placed between the rectifier and the load.A filter circuit is basically a combination capacitors (C) and inductors (L). A capacitor allows the ... Read More