Author name: jojo

Oscillators

LC Oscillators and Types

LC oscillators. LC oscillator is a type of oscillator where a LC (inductor-capacitor) tank circuit is used for giving the required positive feedback for sustaining the oscillations. The LC tank circuit is also termed as LC resonant circuit or LC tuned circuit. According to the Barkhausen criterion for sustained oscillations, a circuit will sustain stable […]

Oscillators

Transistor Oscillators

Essentials of Transistor Oscillators An oscillator must have the following three elements Oscillatory circuit or element. Amplifier. Feedback network. The oscillatory circuit or element, also called the tank circuit, consists of an inductive coil of inductance L connected in parallel with a capacitor of capacitance C. The frequency of oscillation in the circuit depends upon

Oscillators

Oscillator Operation

How an oscillator operates ? Related Articles BASIC OSCILLATORY CIRCUITS TRANSISTOR PHASE SHIFT OSCILLATOR NEGATIVE RESISTANCE OSCILLATORS HARTLEY OSCILLATOR To know the basics of oscillators, its frequency stability, types of oscillations, different types of oscillators and so on, use the tag link – OSCILLATORS A feedback amplifier having closed-loop gain, Af greater than unity can

Oscillators

Frequency Stability of Oscillators

Related Posts OSCILLATOR OPERATION BASIC OSCILLATORY CIRCUITS CLAPP OSCILLATOR WIEN BRIDGE BRIDGE OSCILLATOR LC OSCILLATORS AND TYPES Even if an oscillator is set at an initial frequency, it cannot be maintained throughout. They keep on changing either in a uniform way or sometimes erratically.  the term “frequency stability” is used to define the ability of

Oscillators

Basic Oscillatory Circuits

Related Posts DAMPED AND UNDAMPED OSCILLATIONS OSCILLATOR OPERATION TUNED BASE OSCILLATOR COLPITT’S OSCILLATOR CRYSTAL OSCILLATOR Basic Oscillator Circuit The oscillatory circuit, also called the L-C circuit or tank circuit, consists of an inductive coil of inductance L connected in parallel with a capacitor of capacitance C. The values of L and C determines the frequency

Oscillators

Types of Oscillations

This article has two sections: One discusses criteria for selecting an oscillator while other one discusses various types of oscillations. 1. Selection of an Oscillator 2. Types of Oscillations Criteria for Selection of an Oscillator Here are the parameters that are to be noted while selecting an oscillator for a particular application. Frequency Range. The

Oscillators

Oscillators-An introductory blog post

Introduction to Oscillators An oscillator is the basic element of all ac signal sources. It generates a sinusoidal signal of known frequency and amplitude. An oscillator is one of the most basic and useful instruments used in electrical and electronic measurements. Since sinusoidal waveforms are encountered so frequently in electronic measurement work, the oscillator (sine

Filter Circuits

Active Filter Types

Types of Active Filters Butterworth, Chebyshev, Bessel and Elliptic filters. There are basically 4 types of active  filters. They are butterworth, Chebyshev, Bessel and Elliptic filters. Butterworth Filter: This filter is also called as maximally flat or flat flat filter. This class of filters approximates the ideal filter well in the pass band. Frequency response curves

Filter Circuits

State Variable Filters

With the advancement in IC technology, a number of manufacturers now offer universal filters having simultaneous low-pass, high-pass, and band-pass output responses. Notch and all-pass functions are also available by combining these output responses in the uncommitted op-amp. Because of its versatility, this filter is called the universal filter. It provides the user with easy

Filter Circuits

All pass filters

An all-pass filter is that which passes all frequency components of the input signal without attenuation but provides predictable phase shifts for different frequencies of the input signals. The all-pass filters are also called delay equalizers or phase correctors. An all-pass filter with the output lagging behind the input is illustrated in figure.   The

Filter Circuits

Band Stop Filter

The bandpass fil­ter passes one set of frequen­cies while reject­ing all others. The band-stop filter does just the opposite. It rejects a band of frequencies, while passing all others. This is also called a band-reject or band-elimination filter. Like band­pass filters, band-stop filters may also be classified as (i) wide-band and (ii) narrow band reject

Filter Circuits

Band Pass Filters

Band Pass Filter A band-pass filter is a circuit which is designed to pass signals only in a certain band of frequencies while attenuating all signals outside this band. The parameters of importance in a bandpass filter are the high and low cut-off frequencies (fH and fl), the bandwidth (BW), the centre frequency fc, centre-frequency

Filter Circuits

Higher Order Filters

Higher Order Filters From the discussion made so far on the filters, it may be concluded that in the stopband the gain of the filter changes at the rate of 20 db/decade for first-order filters and 40 db/decade for second-order filters. This means that as the order of the filter is increased, the actual stopband

Filter Circuits

Butterworth Filter

In many low-pass filter applications it is necessary that the closed-loop gain is as close to unity as possible within the passband. The Butterworth filter is best suited for such applications. This filter is also called a maximally flat or flat-flat filter. Ideal and the practical frequency responses for three types of Butterworth low-pass filters

Filter Circuits

Classification of Active Filters

The most widely used active filters are (i)                 low-pass (ii)                 high-pass (iii)                band-pass (iv)               band-stop or band reject (also called the band-elimination or notch) and (v)                 all-pass filters. All of these filters use op-amps as the active elements and R-C networks. Although the 741 type op-amp operates satisfactorily in these filter circuits, high­-speed op-amps like

Filter Circuits

Active and Passive filters

Active and Passive filters – A Comparison: The simplest approach to building a filter is with passive components (resistors, capacitors, and inductors). In the R-F range it works quite well but with the lower frequencies, inductors create problems. AF inductors are physically larger and heavier, and therefore expensive. For lower frequencies the inductance is to

Filter Circuits

Filter Circuits – Active Filters

Introduction to Filters An electric filter is a network designed to attenuate certain frequencies but pass others without attenuation. A filter circuit, therefore, possesses at least one pass band — a band of frequencies in which the output is approximately equal to the input (that is, attenuation is zero) and an attenuation band in which

UPS

UPS-Uninterruptable Power Supplies

Most of us take the mains ac supply for granted and use it almost casually without giving the slightest thought to its inherent shortcomings and the danger posed to sophisticated and sensitive electronic instruments/equipments. For ordinary household appliances such as incandencent lamps, tubes, fans, TV and fridge, the mains ac supply does not make much

Power Supplies

CVT-Constant Voltage Transformer

  With the popularisation of PCs, the constant voltage transformers (CVTs) have also become equally popular. The CVT is simply a magnetic transformer of a special construction that has a capacitor connected across the secondary winding of the transformer. In an ordinary transformer, the primary and secondary windings are wound near each other so that whenever

Voltage Regulators

Switching Regulator using LM1758 A

The National Semiconductor LM 1578 A is a switching regulator which can easily be set up for such dc-to-dc voltage .conversion circuits as the buck, boost, and inverting configurations. The LM 1578 A features a unique comparator input stage which not only has separate pins for both the inverting and non-inverting inputs, but also provides

Voltage Regulators

Switching Regulators Using LM 2575 and LM 2577

Switching Regulators Using LM 2575 and LM 2577 Switching regu­lators are available is different circuit configurations in­cluding the flyback, feed-forward, push-pull, and non-iso­lated single-ended or single-polarity types. Also, the switching regulators can operate in any of three modes – step-down, step-up, or polarity inverting. LM 2575 series of regulators developed by National Semiconductor are monolithic

Voltage Regulators

Switching Voltage Regulators

Switching Voltage Regulators All of the voltage regulators we have discussed so far are series regulators, also sometimes called the linear regulators because the pass transistor used in such a regulator operates in the active region. Series regulators are very popular and meet many of our needs. The main drawback of these regulators is the

Power Supplies, Voltage Regulators

Dual Voltage Supplies

Dual Power Supply using LM 320 and LM 340 Bipolar or dual voltage supplies can be easily designed with the help of two 3-terminal regulators. This is shown in the figure above using the IC’s LM320 and LM 340. Opposite-phase ac is provided by the transformer’s secondary and a grounded center tap. The single full-wave

Voltage Regulators

IC 723 Voltage Regulators

We have already explained in detail about the basics of regulated power supply, voltage regulators and IC voltage regulators. Let us take a look at one of the most popular IC voltage regulators, the 723 Voltage Regulator IC. The functional diagram of the voltage regulator is shown below. It consists of a voltage reference source (Pin

Voltage Regulators

LM340 Series Voltage Regulators

Three terminal voltage regulators This series is typical of the three-terminal voltage regulators. The block diagram is shown in figure. The built-in reference voltage VREF drives the non-inverting input of an op-amp. The operational amplifier consists of several stages of volt­age gain. Because of the high gain of the op-amp, the error voltage between the

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