Basics of Magnetism: Lecture Notes & Slides PDF

19-11-2024 S N FY - Department of Engineering, Sciences and Humanities Basics of...

19-11-2024 S N FY - Department of Engineering, Sciences and Humanities Basics of Magnetism The Earth – Magnetism - Poles FY - Department of Engineering, Sciences and Humanities Why the Earth shows Magnetic properties ? Where is Magnetic North Pole of Earth ? Where is the Magnetic axis ? Is Geographical axis same as Magnetic axis ? Are both axes matching ? Try these questions – What is the exact location of Magnetic Just as a curiosity ! Poles of Earth ?  19-11-2024 Earth as a huge Magnet..... FY - Department of Engineering, Sciences and Humanities The Earth is a huge Magnet with its Magnetic North pole at its Geographical South pole and vice versa..... The origin of Magnetism FY - Department of Engineering, Sciences and Humanities Electron Spin The number of unpaired electrons and their CW or CCW spins are mainly responsible for the Magnetism along with the crystal structure.  19-11-2024 Properties of Magnetic Lines of Force - 1) Magnetic lines are invisible, imaginary lines which are FY - Department of Engineering, Sciences and Humanities somewhat elliptical in shape which never cross eachother. 2) Magnetic lines are closed loops that are supposed to travel from North pole of a bar magnet towards the South pole external to the magnet and from South pole towards the North pole internally. 3) Magnetic lines that are parallel and travelling in the same direction, REPEL eachother. 4) Magnetic lines act like stretched rubber band which always try to contract. 5) Magnetic lines prefer a path of minimum reluctance. Concept of Orientation of Magnetic Flux in a material - FY - Department of Engineering, Sciences and Humanities S N S N S N S N  19-11-2024 FY - Department of Engineering, Sciences and Humanities Cross conductor Dot conductor Will the two conductors attract or repel ? …. And what about this …? Attraction or Repulsion is a property of the direction of magnetic lines FY - Department of Engineering, Sciences and Humanities Cross conductor Dot conductor The conductors will get repelled Lines that are travelling in the same direction REPEL each other The conductors will get attracted Lines that are travelling in the opposite direction cancel each other  19-11-2024 Right Hand Thumb Rule FY - Department of Engineering, Sciences and Humanities Which one of the above is correct ?? Thumb is for Current or Field ?? Match the pairs A B FY - Department of Engineering, Sciences and Humanities 1) Flemings Left hand rule A) Generating action 2) Right hand thumb rule B) Motoring action 3) Right hand grip rule C) Direction of magnetic field due of current in single 4) Fleming’s Right hand rule conductor 5) Faraday’s laws D) Direction of lines of force (North pole) due of current in 6) Lenz’s law coil E) Electromagnetic induction F) Direction of Induced voltage  19-11-2024 Important terms related to Magnetism - Magnetic Permeability (  ) : It is the property of a FY - Department of Engineering, Sciences and Humanities material to allow the magnetic line of force to pass through it. Unit is Henry per meter ( H / meter) Relative Permeability : It is just a ratio for comparison  of the material  r = --------------------------- ( No unit)  of air or vacuum A good ferromagnetic material is about 800 to 1200 times  better than air. Value of r for air = ?? Important terms related to Magnetism - Magneto Motive Force MMF ( F ) : (Similar to EMF) FY - Department of Engineering, Sciences and Humanities F = No. of Turns x Current through them F = N x I Unit = Amp-Turns (OR Amp) Magnetic Flux Density ( B ) : Flux Weber B = ------- Unit is Tesla ( T ) = --------------- Area Sq. meter Magnetic Field Strength OR Magnetic Field Intensity OR Magnetising Force ( H ) : MMF reqd. per meter length Unit is Ampere-Turns per meter ( Amp / meter)  19-11-2024 Important terms related to Magnetism - MMF (F) Amp x Turns FY - Department of Engineering, Sciences and Humanities Flux () = -------------------- = ----------------------- Reluctance (s) (1 / ) x ( l / a) IN Flux () = -------------------- (1 / ) x ( l / a)  l From above we get ,  = ---------- INa We know that, H = B /   INa IN Substituting for B and  , H = --- x --------- = -------- a l l Thus, H is a function of the Current I which produces the Flux ........ H  I Flux density B C OD = Retaintivity FY - Department of Engineering, Sciences and Humanities B Saturation (Residual Magnetism) D Linear rise Magnetism lost A Sluggish start E O H Magnetising Force H OG = Retaintivity G (Residual Magnetism) F Saturation B-H Curve Hysteresis Loop  19-11-2024 Home work – FY - Department of Engineering, Sciences and Humanities 1) Is a good conductor, magnetic in nature ? 2) Is a good magnetic material, a conductor ? 3) What is Curie temperature ? 4) Write on similarities and differences between Electrical and Magnetic circuits S N FY - Department of Engineering, Sciences and Humanities  10-12-2024 FY - Department of Engineering, Sciences and Humanities Actuators Brushless DC Motors FY – DESH – VIT Merits of DC Brush motors – FY - Department of Engineering, Sciences and Humanities 1) Speed control over a wide range is possible. 2) Very high HP capacity motors are available. 3) Moderate technology power supply and starters are sufficient. 4) High expertise not required for maintenance. 5) Cheap and cost effective.  10-12-2024 Demerits of DC motors FY - Department of Engineering, Sciences and Humanities 1) At the Commutator, the brushes are continuously having friction. This causes wear and tear of the brushes as well as the commutator segments. 2) Maintenance cost increases. 3) Heat produces carbon particles at the brush contacts. 4) Frequent replacement of brushes is required. 5) Voltage drop takes place at the brush contacts. 6) To prevent high inrush of current at start, starter is a must. 7) A separate DC power supply is required. 8) Noisy operation. Features of BLDC motors – FY - Department of Engineering, Sciences and Humanities 1) To overcome the problems arising of brush contact issues, BLDC motors are developed. 2) No Left Hand Rule….! Rather, working is based on just a simple Attraction – Repulsion principle between N and S poles. 3) BLDC motors with or without (Hall effect) sensors are available. 4) A specialized motor driver circuit is required. 5) Quiet operation. 6) Moderate and small capacity motors. 7) High power to weight ratio. 8) Good electronic and software control. 9) Low maintenance.  10-12-2024 A brushless DC motor (BLDC) is FY - Department of Engineering, Sciences and Humanities basically a synchronous DC motor powered by direct current (DC) and consists of two main parts: a stator and a rotor. FY - Department of Engineering, Sciences and Humanities 2 Rotor poles (N and S) 6 Stator poles (Temporary) (Permanent) Working Principle – When the stator poles are excited, attraction takes place between opposite poles of stator and rotor, which gives rise to rotation. When the rotor pole approaches an opposite pole of stator, that stator pole is switched off and next stator pole is excited. Thus the rotor pole keeps on chasing stator pole but never becomes successful ….!  10-12-2024 BLDC Motor The Rotor pole keeps FY - Department of Engineering, Sciences and Humanities chasing the opposite pole of the Stator The motor Driver circuit changes the stator polarity at correct moment. Thus, to know exact location of the rotor pole, Hall effect sensor is required. Features of Hall effect sensor – FY - Department of Engineering, Sciences and Humanities Working – Hall effect – When a current carrying conductor is subjected to a magnetic field which is perpendicular to the flow of electric current, an EMF, which is at right angle to the path of the flow of current, changes. The sensor senses this EMF and can detect existence of a magnetic field in the vicinity if it.  10-12-2024 Hall effect sensor in BLDC motor FY - Department of Engineering, Sciences and Humanities Pin configuration and terminals of Hall effect sensor (3144) Types of BLDC motors There are two types of BLDC motors based on the physical design—inner rotor design and outer rotor design. FY - Department of Engineering, Sciences and Humanities The inner rotor design is a conventional design in which the rotor is located at the core (Center), and the stator coil winding surrounds it. In the outer rotor design configuration, the stator windings are located at the core, while the rotor carrying permanent magnets surrounds the stator.  10-12-2024 Types of BLDC motors 1) In-runner motor – The rotor carries the FY - Department of Engineering, Sciences and Humanities permanent magnet poles on it and it is surrounded by the stator with wound pole winding on it. Outer stator with wound poles Inner rotor with permanent poles Types of BLDC motors – 2) Out-runner type – The rotor with permanent magnet poles is outside and FY - Department of Engineering, Sciences and Humanities surrounds the stator with coils in it mounted on the shaft.  10-12-2024 Types of BLDC motors – Axial flux BLDC motor or Flat motor FY - Department of Engineering, Sciences and Humanities 3) Axial flux or Flat motor – The stator and rotor are mounted parallel to each other and face to face. Generally used where there are space constraints. These motors are also called as “Pan Cake” motors. Stator coils are always stationary in all the 3 types. Types of BLDC motors continued– FY - Department of Engineering, Sciences and Humanities Classification based on the sensors Sensor-based BLDC and sensor less BLDC motors. A sensor based BLDC motor is relatively more accurate but costly and is used for a specific applications. BLDC motors are available in different configurations based on stator windings: single-phase, two-phase, and three-phase. Out of these, the three-phase BLDC is the most common.  10-12-2024 Driver for BLDC motor What is a driver circuit ? FY - Department of Engineering, Sciences and Humanities As the rotor approaches the stator pole, it is necessary to change the polarity of the stator pole at right time. So that the rotor will advance further and chase the stator pole. Thus, the position of the rotor should be known. The circuit controlling this is called as a driver circuit. Driver circuits of BLDC motor ….. FY - Department of Engineering, Sciences and Humanities Deglitch What is Deglitch circuit? Glitch is a sudden, usually temporary malfunction or fault of equipment. The deglitch circuit includes a delay block designed using Logic Gates. The delay block is coupled to receive a data signal from the signal producing node and to produce a delay data signal.  10-12-2024 Driver for BLDC motor FY - Department of Engineering, Sciences and Humanities Driver circuit with the Hall effect sensor The electronic circuit switching the stator poles is called as the driver circuit. Sensor less BLDC Motor Control This method uses back EMF for determining the location of the motor's rotor (the motor's FY - Department of Engineering, Sciences and Humanities rotating part) with respect to the motor's stator (the stationary part). A voltage applied across a motor's winding forces the motor's rotor to turn. The movement of the rotor through the motor’s magnetic field, however, is analogous to the behavior of a generator, and consequently the winding not only receives an applied voltage but also generates its own voltage. This voltage is referred to as back electromotive force, or back EMF, and it is proportional to the motor's rotational speed. Back EMF can be used to determine a motor's rotor speed and position—no sensors are required. Controlling a motor by means of back EMF is not a simple task; most sensor less BLDC motors are controlled using a microcontroller, a digital signal processor, or a dedicated driver IC.  10-12-2024 Sensor less BLDC Motor Control FY - Department of Engineering, Sciences and Humanities Applications of BLDC motor CNC machines FY - Department of Engineering, Sciences and Humanities Robotics Position control systems Electric vehicles Washing machines Hard drives of PC DVD drives Ceiling fans (new) Blowers Air conditioners Refrigeration systems Aeromodelling Drones …… and many more FY - Department of Engineering, Sciences and Humanities 10-12-2024 FY - Department of Engineering, Sciences and Humanities FY - Department of Engineering, Sciences and Humanities Enclosures DC Motors FY - Department of Engineering, Sciences and Humanities FY - Department of Engineering, Sciences and Humanities Construction of DC Machine DC Motors symbolic representation  Construction of DC Machine FY - Department of Engineering, Sciences and Humanities FY - Department of Engineering, Sciences and Humanities Commutator is divided into 2 halves called as segments. Practically, no. of segments = no. of slots in the armature FY - Department of Engineering, Sciences and Humanities FY - Department of Engineering, Sciences and Humanities Commutator Slots Armature Shaft Winding Armature  Armature Winding FY - Department of Engineering, Sciences and Humanities Pole 2 Pole 1 Brushes Commutator + External DC supply connections – 1) Right hand thumb rule 2) Right hand grip rule FY - Department of Engineering, Sciences and Humanities 3) Fleming’s right hand rule – Generating action 10  4. Fleming’s left hand rule – Motoring action FY - Department of Engineering, Sciences and Humanities 11 Motoring Action – How a DC motor works ? Main Flux N FY - Department of Engineering, Sciences and Humanities N Dense Flux Weak Flux F Armature Flux F S S Main Flux A Couple is generated  Direction of rotation of DC motor Main Flux Assume that the motor starts and N FY - Department of Engineering, Sciences and Humanities goes through 1800 of rotation. So, what is the new direction ???? Same or Reversed ???? S Main Flux How do we get a unidirectional rotation ? FY - Department of Engineering, Sciences and Humanities Main Flux When a DOT goes from N to S, it no more N remains DOT when it reaches S. Rather it reverses the direction of current through itself and becomes a CROSS. Exactly opposite thing happens in case of the CROSS under S pole. This amazing change takes place because the COMMUTATOR ! S Main Flux  Concept of Back EMF Main Flux When a motor starts rotating, the conductors cut the main N flux in the air gap. FY - Department of Engineering, Sciences and Humanities This cutting of Flux gives rise to an EMF in the conductors. (Generating action) This EMF should oppose the cause producing it. (Lenz’s Law) This EMF opposes the cause i.e. the supply voltage V. Therefore this EMF is called as Back EMF (Eb) or Counter EMF. S Thus, V = – Eb Main Flux V is supply voltage and Eb is generated EMF. EMF Equation..... P = Number of poles of the machine. ϕ = Flux per pole in Weber. FY - Department of Engineering, Sciences and Humanities N = Speed of Armature in Revolutions per Minute (RPM). N Z = Total number of Armature conductors. A = Number of Parallel paths in the Armature winding. According to Faradays Law, dϕ e = ------ Volts dt Total Flux cut e = ------------------ Volts Time required S In one Revolution of the armature, the total flux cut by one conductor will be e=Pϕ Weber......(eq.1) RPM = Revolutions per Minute = N RPS = Revolutions per Second = N / 60 Seconds for one Revolution = 60 / N.......(eq.2)  EMF Equation.....contd. According to Faradays Law, Total Flux cut FY - Department of Engineering, Sciences and Humanities e = ------------------ Volts Time required Substituting from eq.1) and eq.2) we get, Total Flux cut Pϕ PϕN e per conductor = ----------------- = -------- = --------- Volts Time required 60 / N 60 There are total Z conductors, but all of them are not in series ! They are equally divided in A parallel paths (groups). Thus Z/A conductors are in series. Thus, PϕN Z PϕNZ Total E = ------- x --- = ---------- Volts 60 A 60 A This is called as the EMF Equation of a DC Generator. E  ?? E  N All other parameters are constant DC Shunt Motor Im – Ish = Ia V – Ia Ra = Eb FY - Department of Engineering, Sciences and Humanities Some typical practical values of different parameters of a DC shunt motor are ….. V = 230 V DC Im = 10 A (depends upon HP) Ia = 9 Amp Ish = 1 Amp Ra < 1.0 ohm Rsh = 200+ ohm V drops at brushes also. Eb = 227  228 V  Power equations of DC motor Eb = V – Ia Ra ….. Multiply both sides by Ia Eb Ia = V Ia – Ia2 Ra …….(1) This is a power equation now… FY - Department of Engineering, Sciences and Humanities Eb Ia = Input – Loss (Heat generated) Eb Ia = Output (IMP parameter) But Eb = P  N Z / 60 A ….. Substitute in (1) PNZ Eb = ----------- x Ia = T x  …(Elect to Mech) 60 A But  = 2 N / 60 This is the Torque equation of DC Motor 1 P  Z Ia Thus….. T = ------ x ------------- N-m T   Ia 2 A …(Other parameters are constant) P NZ Eb = ----------- (basically Eb is a generated EMF) FY - Department of Engineering, Sciences and Humanities 60 A Eb   N N  Eb /  Eb V – Ia Ra N  ------- = -------------- ϕ ϕ  Effect of loading on the motor CURRENT FY - Department of Engineering, Sciences and Humanities N (V – IaRa) When Motor is loaded, the speed has to drop. Eb depends on speed, hence it drops so Ia increases DC Motor characteristics – Eb V – Ia Ra 1 FY - Department of Engineering, Sciences and Humanities N  ------ N  ------- = -------------- Ia ϕ ϕ 1 P  Z Ia T = ------ x ------------- T  Ia 2 A Characteristics are graphical relations between Ia, T and N  DC Motor characteristics – 1 N N  ------ FY - Department of Engineering, Sciences and Humanities Ia Ia T  Ia T Ia Draw a graph for the relation between T and N. N ? T FY - Department of Engineering, Sciences and Humanities Problems on DC machines  1. Armature of a 4 pole generator is wound with 496 conductors. The flux and speed are such that the average emf generated in each conductor is 1.5 V. The current in each conductor is 105 amps. Calculate the total FY - Department of Engineering, Sciences and Humanities current and generated emf of the armature if the winding is connected in a) wave and b) lap. Also determine the power generated in each case. 2) Armature of 6 pole generator is wound with 564 conductors and driven at 800 rpm. The flux per pole is 20 mWb. The current in each conductor is 75 A. Calculate total current, generated emf, and total electrical power FY - Department of Engineering, Sciences and Humanities generated if the conductors are connected in a) wave and b) lap.  3) A DC motor connected to a 450 V supply takes current of 120 A on full load. If the armature circuit resistance is 0.15 Ω and field circuit resistance is 150 Ω, calculate the value of back emf at this load. FY - Department of Engineering, Sciences and Humanities 4. A 4-pole, 500 V dc motor takes an armature current of 80 A when operated at rated voltage. Armature resistance is 0.4Ω. The armature is wave wound with 522 conductors and useful flux per pole is 0.025 Wb. Calculate a) the FY - Department of Engineering, Sciences and Humanities back emf of the motor, b) the speed of the motor and c) torque in Nm developed by the armature.  5) A 120 V dc shunt motor has an armature resistance of 0.2 Ω and a field resistance of 60 Ω. It runs at 1800 rpm taking full load current of 40 A. Find the speed on half load conditions. (1860.85 rpm) FY - Department of Engineering, Sciences and Humanities 6) A 250 V dc shunt motor has Ra = 0.08Ω. When connected to 250 V dc supply, it develop[s back emf of 242 V at 1500 rpm. Determine--- 1. Armature current, 2) Armature current at start and, 3) Back emf if armature FY - Department of Engineering, Sciences and Humanities current is changed to 120A.  7) The lap wound armature of a 4 pole dc shunt motor has 600 armature turns and it takes 100 amps when running at 600 rpm. The flux per pole is 100mWb. Calculate the gross mechanical torque developed and the net FY - Department of Engineering, Sciences and Humanities power output if the torque lost in friction, windage and core losses is 60 N- m. N FY - Department of Engineering, Sciences and Humanities F F S Thank you A Couple is generated FY - Department of Engineering, Sciences and Humanities Servo Motors  SERVO MOTOR BLDC MOTOR A servo motor is a self-contained electrical device that moves parts of a machine with high efficiency and great precision. In simpler terms, a servo motor is a BLDC motor with a sensor for positional feedback. This allows the output shaft to be moved to a particular angle, position, and velocity that a regular motor cannot do.  SERVO MOTOR However, a servo motor is only one part of a closed-loop motion control system. A complete motion system includes an amplifier, control circuit, drive gears, potentiometer, shaft, and either an encoder or resolver as well as the servo motor. Unlike large industrial motors, a servo motor is not used for continuous energy conversion. Servo is an electromagnetic device uses a negative feedback mechanism to converts an electric signal into controlled motion. (it reduces the sensitivity to parameter variation. Negative feedback in a control system reduces the overall gain/ Negative feedback refers to a case where outputs from a system are subsequently fed back into it, minimizing or reducing the effect of  Servo Or Stepper? While both kinds of motors can control speed and position, they are both designed for very different applications. Stepper motors have built-in steps allowing the controller to signal how many steps to make, however, this only works if the controller knows the position of the output shaft. Because of this, when a stepper motor is powered up the controller moves the output shaft to a known position or until it activates an end limit switch. A servo motor uses a sensor to know the position of its output shaft so that when it is powered on it can immediately go to the desired position.  What is Servo Motor? Basically, servos behave like as actuators which provide precise control over velocity, acceleration, and linear or angular position. It consists of four things: DC motor, position sensor, gear train and a control circuit. The gear mechanism connected with the motor provides the feedback to the position sensor. The gear of the servo motor is generally made up of plastic but in high power servos, it is made up of metal.  Types of Servo Motors On the Basis of Rotation Positional Rotation Servos: Positional servos can rotate the shaft in about half of the circle. Also, it has the feature to protect the rotational sensor from over-rotating. Positional servos are mainly used in limbs, robotic arms, toys etc  Servo Motor ✓ Gearing mechanism – FY - Department of Engineering, Sciences and Humanities A train of gears reduces the speed of the motor and consequently increases the Torque at the output shaft. The speed is dropped to a very low value e.g. 30 – 40 rpm using suitable gear ratio. Why the Torque increases ? P = T x  But,  = 2 N / 60 For the same P = T x  FY - Department of Engineering, Sciences and Humanities Servo Motor ✓ Position sensor – A Potentiometer is connected to the end of the gear train which turns through the same angle as that of the last gear. The resistance is measured and position is calculated.  Control Circuit Block diagram FY - Department of Engineering, Sciences and Humanities Potentiometer Position Feedback Rotate Feedback info. Servo Micro Controller Control Motor Position Command Drive Current Unit A rotary potentiometer is a variable resistance device that can be used to measure angular position Through voltage division the change in resistance can be used to create an output voltage that is directly proportional to the input displacement. FY - Department of Engineering, Sciences and Humanities Servo Motor – types Eb V – Ia Ra N  ------- = -------------- ϕ ϕ Speed control of Servo motor can be done in following way …. 1) Armature voltage controlled motor – The voltage given to the armature of the motor comes from the servo system of the motor. 2) Field (Flux) controlled motor – The voltage given to the field winding of the motor controls the flux and thus the speed.  Types of Servo Motors Continuous Rotation Servos: Continuous servos are similar in construction to the positional servo. But, it can move in both clockwise and anticlockwise directions. These types of servos are used in radar systems and robots. Linear Servos: Again linear servos are also like a positional servo, but with additional gears to the adjust the output(rack and pinion gear) from circular to back-and-forth. These type of servos are used in airplanes  Advantages Of Servo Motors Precision Control: Servo motors provide precise control of position, speed, and torque, making them ideal for applications where accuracy and repeatability are critical. Encoder determines accuracy and resolution. High Torque: Servo motors are designed to provide high torque at all speeds, which makes them well-suited for applications that require high starting torque and move loads at high speeds. High torque to inertia ratio. Servo Motors can rapidly accelerate loads. Has 5-10 times more rated torque for short periods. Fast Response Time: Servo motors have a very fast response time, which makes them ideal for applications that require rapid acceleration. Advantages of Servo Motors Wide Speed Range: Servo motors are capable of operating at a wide range of speeds, from very slow to very fast, without losing accuracy or precision. In servo motor, the High-speed operation will be possible. High output power relative to motor size and weight. Servo motors achieve high speed at high torque values. High output power relative to motor size and weight. High efficiency. It can approach 90% at light loads. Quiet at high speeds. Disadvantages of Servo Motors The cost will be higher. Servos Motors requires tuning to stabilize the feedback loop. Servo Motor will become unpredictable when something breaks. So, safety circuits are required. Complex controller requires encoder and electronic support. Peak torque is limited to a 1% duty cycle. Servo Motors can be damaged by sustained overload. Gear boxes are often required to deliver power at higher speeds.  Applications of Servo motor – 1) Position control systems FY - Department of Engineering, Sciences and Humanities 2) Robotics 3) CNC machines 4) Automation conveyors 5) Navigation systems 6) Solar tracking systems 7) Radio Antennas & Observatory 8) Auto focus cameras 9) Textile and Printing machinery FY - Department of Engineering, Sciences and Humanities  What is a Servo Motor ? ✓ A Servo motor is essentially a FY - Department of Engineering, Sciences and Humanities combination of a DC/AC motor, a Gearing mechanism, Position sensor, Feedback circuit, Control circuit etc. housed together. ✓ The main feature of a Servo motor is that it can rotate through a few specific degrees in addition to ✓This feature makes the servo motor a its capability to rotate continuously. best choice for position control in Robotics and CNC machines.  FY - Department of Engineering, Sciences and Humanities HMK 1  Flow of Information and Energy – Sensor FY - Department of Engineering, Sciences and Humanities Sensor – It is a device which will understand some change taking place in the surrounding and will create a response signal for the same. For e.g. – Eye of a human body – senses the light rays coming from a surface. Thermometer – Mercury in the thermometer senses the temperature of a body.  Flow of Information and Energy – Sensor Transducer FY - Department of Engineering, Sciences and Humanities Transducer – It is a device which will collects the findings from a sensor and converts it proportionately into some other suitable quantity. (generally electrical) For e.g. – A a microphone senses sound waves and converts to electrical signal. On the contrary a loudspeaker senses the electrical signal and converts it into sound waves. In some cases the sensor and transducer are one single device. FY - Department of Engineering, Sciences and Humanities Flow of Information and Energy – Controller Actuator Plant Transducer Sensor Controller – This is the Brain of the system which makes decisions and sends orders to the actuator to work as per the signals received.  Flow of Information and Energy – FY - Department of Engineering, Sciences and Humanities Sensor Transducer Controller Actuator Actuator – It is the Linear or Rotational motion creating device of the system. Types of Actuators – 1) Pneumatic (Air pressured) 2) Hydraulic (Oil or Water pressured) 3) Electric (Motors or Solenoids) FY - Department of Engineering, Sciences and Humanities Hydraulic Actuators :  Hydraulic System : Components of Hydraulic System FY - Department of Engineering, Sciences and Humanities Reservoir Pump For High Pressure For High Discharge Direction Control Valve Flow Control Valve Pressure Control Valve Connectors 4-Ports 3-Positions Pressure Control Actuators: Hence 4/3 DCV Direction Flow Reservoir: Pump: ControlControlValve: Valve: It cab be rotary or ItValve: It It is is used for Oil is used to to control storage pressure maintain the andthe It transltory It is used totype. direct the flow oil rate conditioning and tosend or of from oil it to the the is used Generally release a piston some flow actuator The from pump hence to part additives actuator. cylinderof oilforback aretoadded linear and Spring is for reset actuator controlling in The reservoir ports Pressure the to and maintain is the Dotted line is pilot reservoir flow motorsto maintain for rotory supply accordingly actuation the oil design property allows speed. requirement the ofin Arrow is pressure the required is preferred. pressure actuator the work. Hydraulic System relief direction Actuator  Diaphragm Single Acting Double Acting Rotary Vane Pump Rotary Piston Pump Radial Piston Pump FY - Department of Engineering, Sciences and Humanities Direction Control Valves  Hydraulic System : Components of Hydraulic System FY - Department of Engineering, Sciences and Humanities Reservoir Pump Direction Control Valve Flow Control Valve Pressure Control Valve Connectors Pressure Actuators: LEVER Control and SPRING Direction Flow Reservoir: Pump: Control ControlValve: Valve: It cab Lever be isOilrotary atopart or to ItValve: It It is is used for is used to control storage pressure maintain the andthe It transltory operate It is used thtotype. actuator direct and the flow oil rate conditioning and to send or of from oil it to the the is used Generally springe is release a piston used to some reset flow actuator The actuator.from pump hence additives are to added part cylinderof oil it.reservoir The forback inclined linearto and arrow actuator controlling in The ports Pressure the to and maintain is the reservoir flow motors represents tothemaintain for rotory variable accordingly actuation the oil design property allows speed. requirement the ofin the required is preferred. pressure actuator the work. Hydraulic System Actuator FY - Department of Engineering, Sciences and Humanities Hydraulic Actuators : Useful Features : Hydraulic actuators are rugged and robust. Best suited for high force / power applications. A hydraulic actuator can hold force and torque constant without the pump supplying more fluid. Hydraulic actuators can have their pumps and motors located a considerable distance away with minimal loss of power. Disadvantages : Leakage of fluid is a common issue in Hydraulic system. The efficiency drops. Hydraulic actuators require many spares parts. FY - Department of Engineering, Sciences and Humanities Hydraulic Actuator – Fluid pressure is used Hydraulic Actuators – 1) Linear type 2) Rotary T  Pascal's law Pascal's law (also called Pascal's Principle) is a the fundamental law in hydrostatic. It states that "a change in the pressure at any point of an enclosed incompressible fluid is conveyed undiminished to every part of the fluid and to the surfaces of its container  Hydraulic Linear Actuators – Basic Working Principle – Highly Accurate and Precise FY - Department of Engineering, Sciences and Humanities Power is not hindered by geometry of the machine Power capacity is extremely Large Flexible and Easy Control Instant and Smooth reversal of motion Provides fast response It can varied from delicate touch to several hundred tons System has highest power to weight ratio. FY - Department of Engineering, Sciences and Humanities Hydraulic Linear Actuators – Application Prototype FY - Department of Engineering, Sciences and Humanities Hydraulic Linear Actuators – Simple Hand Pump – Delivery Suction FY - Department of Engineering, Sciences and Humanities Hydraulic Linear Actuators – Car washing system The Return supply is restricted to pass through Flow control valve. Thus the adjusted flow rate allows to lower the load at required safe speed. Hence fall safe circuit.  Pneumatic Actuators : Pneumatic actuators operate on the principle of converting compressed air into mechanical motion. In a pneumatic actuator, compressed air fills a chamber, creating a force that moves a piston or rotates a shaft.  Pneumatic Actuator – Air pressure is used FY - Department of Engineering, Sciences and Humanities Pneumatic Actuators – 1) Linear type FY - Department of Engineering, Sciences and Humanities Pneumatic System FY - Department of Engineering, Sciences and Humanities Pneumatic Actuators : Useful Features :- Fast process. Can be used in areas of extreme temperatures. Disadvantages :- Limited stroke length. Loss of Air Pressure is always a problem. Entry of a moisture in the system, drops the air pressure. Air may be contaminated by moisture, oil or lubrication, leading to downtime and maintenance. Low pressure system as compared to hydraulic system. Noisy operation.  Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type FY - Department of Engineering, Sciences and Humanities FY - Department of Engineering, Sciences and Humanities Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type FY - Department of Engineering, Sciences and Humanities Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type  Pneumatic Actuator – Air pressure is used FY - Department of Engineering, Sciences and Humanities Pneumatic Actuators – 1) Linear type FY - Department of Engineering, Sciences and Humanities Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type  Pneumatic Linear actuator in packaging industry - FY - Department of Engineering, Sciences and Humanities Co-ordinated sequencing of both the pneumatic cylinders. FY - Department of Engineering, Sciences and Humanities Pneumatic Actuator used to convert Linear to Rotary Motion Air pressure inlet and outlet FY - Department of Engineering, Sciences and Humanities Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type  Pneumatic Actuator – Air pressure is used Pneumatic Actuators – 1) Linear type 2) Rotary type FY - Department of Engineering, Sciences and Humanities Inlet and Outlet for air from compressor  Electric Actuators : Electric actuators use force generated by electric motors to power a number of critical tasks in industrial operations. The actuator assembly triggers the electric motor to generate force, which is then directed based on the desired action or movement. Electric actuators can use a feedback mechanism to read information about the position of the piston rod. They can be preprogrammed to move to specific positions in a sequence or to move from a secondary position back to the resting position.