If a circuit has no power a circuit would not be able to perform its desired function. Whether youre new to designingin a power supply or dcdc converter or an old hand, this book offers an invaluable resource and all the information youll need in one easy. Never touch exposed wiring, connections or any live circuit when attempting to take measurements. Most students of electricity begin their study with what is known as direct current dc, which is electricity. In either case, however, it is the end use conditions that apply and it is the end use standards that must be considered with respect to. Figure 4 illustrates several commonly used dc dc converter circuits, along with their respective conversion ratios.
Depending on its design, a power supply may obtain energy from. Basic ac theory i i direct current dc alternating current ac i i figure 1. Power supplies and linear regulators our objective is to examine characteristics, schematics, analysis, design and limitations of practical power supplies with ic regulators. One widely used approach uses the on and off times pulsewidth modulation pwm to control the power. An essential part of an acdc power supply circuit is the. Regulated power supply circuit diagrams and working. Dc motor principle a machine that converts dc power into mechanical energy is known as dc motor. A power supply whose input rectifier circuits operate directly from the ac power line, without transformer. Batteries or power supplies are mostly used to produce a steady d. Dc circuits and electrical power university of plymouth. A hypothetical ideal switchedmode power supply dissipates no power. Direct current dc electrical circuits by ron kurtus. Similarly, items such as books and jackets should not be left on top of the test equipment as it could cause overheating.
Power supplies and linear regulators university of kansas. Consider a circuit in which there is an initially uncharged capacitor, a dc power supply, a resistor, and an initially open switch this is commonly called an rc circuit. More cost effective than a transformerbased or switcherbased power supply. Constructing your power supply layout considerations 41. In other words, it is a measurement of the work required to move a unit charge between two points. The insulated type circuit is also known as the primary power supply main power supply. Find the total contribution by adding algebraically. Power supplies, mpumcubased systems, industrial controls, computer systems and many other product applications are requiring power supervisory functions which monitor voltages to ensure proper system operation. We know that under dc conditions the capacitor appears as an open circuit no current flowing through it. The main object is to guide the designer in selecting the topology with its associated power semiconductor devices. Whenever current increases, voltage must decrease, and whenever current decreases, voltage must increase. Ac circuits dc circuits discrete components digital circuits general example question. Dc power supply and a quality dmm capable of reading dc voltage, current and resistance. Every circuit designed today needs power to be applied for the circuit to function.
Switches are used everywhere to open and close circuits. Transformerless power supply design designer circuits. A 5 volt dc power supply will vary its current based upon the circuit attached. A designers guide to instrumentation amplifiers, 3rd edition. This means there is no voltage difference between the two. Digital dc regulator if you are looking for 5v dc power supply for the digital circuit. The level is necessarily technical, but readable for engineers, designers and students. The ratio of on time to the switching period time is the duty cycle. In summary, this is a book written not for the theorist, but for the user attempting to solve both traditional and.
Dc dc power supply, which will provide improved output regulation. A circuit that can be ac or dc is the combination of active elements power supply sources and passive elements resistors, capacitors and inductors. Figures 1 and 2 show the simplest rectifier circuits. Transformer is used to stepup or stepdown usually to stepdown the supply voltage as per need of the solidstate electronic devices and circuits to be supplied by the. Turn off all independent sources except one source. Motorola offers a wide range of power supervisory circuits that fulfill these needs in a cost effective and efficient manner. The output of the dc power supply is used to provide a constant dc voltage across the load. Dc power suppliesintroduction electronic circuits and. Antoniazzi in mainssupplied electronic systems the ac input votlage must be converted ni to a dc voltage wthi the right value and degree of stabilization. Almost all the projects in class will be powered by dc electricity. A regulated dc power supply is essentially an unregulated power supply with the addition of a voltage regulator. The type 1265a adjustable dc power supply figure 11 is a multi range unit that provides high power to a wide range of load resistances.
The v is for voltage, which means the potential difference between two charges. In electrical engineering, there are basically two types of voltage or current electrical energy source which defines the. This simple fact, unfortunately, has an adverse effect on power supply circuits. Circuit theorypower supplies wikibooks, open books for an. The circuit diagram, often referred to as a chopper circuit, and its principal waveforms are represented in figure 1. Thus, the circuit theory or analysis helps to understand the circuit behavior or characteristics by finding out the voltages and currents in various elements in a circuit by using different. A designers guide to instrumentation amplifiers by charles kitchin and lew counts 3rd edition. Module 2 basic dc theory this module describes the basic concepts of direct current dc electrical circuits and discusses the associated terminology. Preface from the author the function of any ac dc or dc dc converter module is to meet one or more of the following requirements. This law states that the current in a circuit is directly proportional to the potential. Dc is the basis for most circuit designs that goes into everyday products. Electronic devices and circuits pdf 3p this book is intended as a text for a first course in electronics for electrical engineering or physics students, has two primary objectives. Basic acdc power supplies this worksheet and all related. It will cover some the basics of electric circuit theory, circuit analysis, and will touch on circuit design.
The reliability and performance of the electronic system proper design of power supply is necessary. Its operation is based on the principle that when a current carrying conductor is placed in a. Introduction electric circuit theory and electromagnetic theory are the two fundamental theories upon which all branches of electrical engineering are built. A regulated power supply essentially consists of an ordinary power supply and a voltage regulating device, as illustrated in the figure. Regulated power supplyblock diagram,circuit diagram,working. In these basic configurations the peak voltage across the load is equal to the peak value of the ac.
Direct vs alternating current distribution systemsthat are far more ef. Free electronic circuits books download ebooks online. Many branches of electrical engineering, such as power, electric machines, control, electronics, communications, and. For example, we cant think of television, computer, radio, telephone, mobile as well as measuring instruments like multimeter etc. Switch semiconductor and integrated circuit devices. A path between two or more points along which an electrical current can be carried is called a. Science 14 lab 3 dc circuits theory all dc circuit analysis the determining of currents, voltages and resistances throughout a circuit can be done with the use of three rules. I will show you, 12v to 5v converter step down regulator.
When the switch is first closed, neither plate has charge on it. The input supply voltage is 15v dc so the v 15v dc and the power flowing through the circuitry is 30w, so, the p 30w. Constant current power supply a regulated power supply that acts to maintain its output current constant in spite of changes in load, line, temperature, etc. This circuit is used to convert the dc supply into high frequency, high current ac, which by various means, depending on the design of the circuit, is reconverted into a regulated dc output. Generate the dc voltages needed for most electronics. The function of any acdc or dcdc converter module is to meet one or more of the following requirements. This book provides an excellent introduction to electronic circuit design. Relationship between voltage current and resistance. In each example, the switch is realized using a power. So this combination of voltage regulating devices with the ordinary dc power supply is called as regulated dc power supply. This type is widely used for the ac dc converters that generate dc power mainly from a commercially available ac source 100v to 240v or for the applications that require the insulation between the input side and the output side to eliminate noises. Volume 2 of 4 module 3 dc circuits this module introduces the rules associated with the reactive components of inductance and capacitance and how they affect dc circuits.
Power is defined as voltagecurrent the current within this equation comes in two flavors ac and dc. Free electronic circuits books download ebooks online textbooks. Dc circuits open textbook library center for open education. The handbook of electric power calculationsprovides detailed stepbystep calculation procedures commonly encountered in electrical engineering. By presenting intuitive descriptions of the power supply systems operation along with commonly used circuit approaches. Looking over his notes from ac theory, the student proceeds to build this power supply circuit complete with a lowpass. The current passing through z1 can go one of two places. Circuit theory i superposition steps to apply superposition principle.
Dry cells and batteries can be used for this purpose. For a given amount of power, theres an inverse relationship between voltage and current. Circuit theoryall chapters wikibooks, open books for an. To explain the details of why this is so, a bit of background knowledge about ac. It changes in most cases reduces the level of supply to a value suitable for driving the load circuit. This book will serve as a companion reference for a 1st year of an electrical engineering undergraduate curriculum.
A student learns that a rectifier circuit is often followed by a lowpass filter circuit in an ac dc power supply to reduce ripple voltage on the output. A dc power supply unit commonly called a psu deriving. Avoid shorting circuit the output of dc power supply. Part i provides an introduction to basic electronic theory and part ii is designed to be a practical manual for designing and building working electronic circuits. Converter circuit topologies a large number of dc dc converter circuits are known that can increase or decrease the magnitude of the dc voltage andor invert its polarity 15. Power supply design tutorial february 8, 2018 jurgen hubner this series of tutorials explains indepth design steps for the buck and the boost topology dc dc switching regulators, supplemented by dedicated sessions on pcb layout and signal edge control for emi that apply to all switching regulators. The handbook contains a wide array of topics and each topic is written by an authority on the subject. Find the output voltage or current due to that active source using nodal or mesh analysis.
In this circuit total power consumption across the load is 30 watt, if we connect 15v dc supply, how much current is required. Introduction to dc circuits electric voltage and current. Below circuit shows ordinary or unregulated power supply. This allows the voltage to stay stable regardless of the amount of current consumed by the load, provided the predefined limits are not exceeded. In order to be able to work with dc we need to convert the alternating current ac from the outlets into a direct current, which we use to power our circuits. Sharpen your technical mastery of dc power supplies and keep your electronics career on the fast track with dc power supplies, by joseph j. Mode power supply reference manual should prove useful.
For equipment, each lab station should include a dual adjustable dc power supply and a quality dmm capable of reading dc voltage, current and resistance. This is why they are part of circuit theory from the very beginning. They are the start mechanism that sets an electrical process in motion. Thus, if it is operating a circuit and the ac power fails, the power supply will again start supplying power when the ac power comes back on. Power supply is more efficient than a resistive transformerless power supply discussed next. When we see a value such as 10 volts, it is a measurement of the potential difference between two. A student learns that a rectifier circuit is often followed by a lowpass filter circuit in an acdc power supply to reduce ripple voltage on the output. Electrical books teach yourself electricity and electronics this book is for people who want to learn basic electricity, electronics, read more pdf electromagnetism lecture notes university of cambridge the. Though designs may vary, the task of converting ac power to dc power is vital in the functioning of a great many electronic devices. This higher power conversion efficiency is an important. Constant power loss the zener diode introduces a nonobvious drawback common to all transformerless power supplies. The electrical power is almost exclusively generated, transmitted and distributed in the form of ac because of economical consideration but for operation of most of the electronic devices and circuits, dc supply is required. The input to a dc dc converter is an unregulated dc voltage vg.
Here are two simple acdc power supply circuits, one without a. The correct answer to the example question is c circuit. The handbook includes information on alternating current ac and direct current dc theory, circuits, motors, and generators. This book covers direct current dc circuit theory and is broken up into three modules. The treatment throughout the handbook is practical with very little emphasis on theory. More exactly, load transient recovery time for a cv supply is the. Working with current sources inside op amps and transistors has few safety risks. Looking over his notes from ac theory, the student proceeds to build this. Recoms ac dc and dc dc books of knowledge are a detailed introduction to the various converter topologies, feedback loops analogue and digital, test and measurement, protection, filtering, safety, reliability, constant current drivers and applications. This paper presents an overview of the most important dc dc converter topologies. Source every power supply must obtain the energy it supplies to its load, as well as any energy it consumes while performing that task, from an energy source. The direction and magnitude of the electrons flow however depend on the kind of source. Topics covered include ac and dc circuits, passive circuit components, phasors, and rlc circuits. Jan 24, 2018 an electrical circuit is a complete conductive path through which electrons flow from the source to the load and back to the source.
There is no relationship between the current voltage through a power supply. A general power supply unit has the following basic units. Design a simple dc power supply michigan state university. A companion laboratory manual for ac electrical circuits is also available. A nice feature for unattended operation is that the power supply can be set to have its output on at the last power on settings.
The output from an ordinary power supply is fed to the voltage regulating device that provides the final output. Voltage regulation is achieved by varying the ratio of ontooff time also known as duty cycles. Dc input this power management subsystem employs a power supply that accepts a dc voltage input, typically 5 v, 12v, 24v, or 48 v and produces a dc output voltage. Dc motors although ac motors are used in most of the cases, dc motors have many applications and used for multipurpose applications. Module 1 covers the basics for circuits that include dc sources voltage or current and resistors. Not isolated from the ac line voltage which introduces safety issues. How a power supply regulates voltage in electronic circuits. The output voltage rating of a power supply operating in the constant current mode analogous to the output current rating of a supply operating in the constant voltage mode. Repeat step 1 for each of the other independent sources.
Power supplies can typically be divided into two categories. Whether you are an experienced power supply designer, designing your first switching power supply or responsible for a make or buy decision for power supplies, the variety of information in the switch. The switching power supply continues to increase in popularity and is one of the fastest growing markets in the. Let us briefly outline the function of each of the elements of the dc power supply. In contrast, a linear power supply regulates the output voltage by continually dissipating power in the pass transistor. Dc dc power converters are employed in a variety of applications, including power supplies for personal computers, office equipment, spacecraft power systems, laptop computers, and telecommunications equipment, as well as dc motor drives.
The function of any ac dc or dc dc converter module. Looking over his notes from ac theory, the student proceeds to build this power supply circuit complete with a lowpass filter at the output. Circuit design guide for dcdc converters110 your analog. Its your complete, ontothejob guide to building virtually every kind of internal and external dc power supply highvoltage, remote, portable and emergency. The purpose of a power supply is to provide power for an electronic circuit.