35653186 Project on Inverter

PROJECT ONPROJECT ON12 v dc-220 v ac12 v dc-220 v ac

INVERTER INVERTER

Submitted bySubmitted byDebasish Sarkar-0301227126Debasish Sarkar-0301227126

Manoj Sethi-0301227128Manoj Sethi-0301227128Himanshu Malik-0301227130Himanshu Malik-0301227130

Sandeep Sidharth-0301227377Sandeep Sidharth-0301227377

UNDER THE GUIDANCE OFER. S.K MAHAPATRAER. S.M.S ROUT

INTRODUCTION :-INTRODUCTION :- Today the power supply unit is the most essential for Today the power supply unit is the most essential for

us. Power failure, power shading cause deep trouble us. Power failure, power shading cause deep trouble in some operation. Thus inverter is the ideal choice in some operation. Thus inverter is the ideal choice in the time of power cut. Inverter will supply in the time of power cut. Inverter will supply emergency power to system. emergency power to system.

DC-to-AC converters are known as inverter. It DC-to-AC converters are known as inverter. It change a dc input voltage to a symmetrical ac change a dc input voltage to a symmetrical ac output voltage of desired magnitude and output voltage of desired magnitude and frequency. The output voltage invert of ideal frequency. The output voltage invert of ideal inverters should be sinusoidal. inverters should be sinusoidal.

Inverters are widely used in industrial Inverters are widely used in industrial applications (e.g., variable speed ac motor drives, applications (e.g., variable speed ac motor drives, induction heating, standby power supplies, induction heating, standby power supplies, uninterruptible power supplies). The input may be a uninterruptible power supplies). The input may be a battery, fuel cell, solar cell or other DC source. battery, fuel cell, solar cell or other DC source.

FEATURES :- FEATURES :-

BJT based inverterBJT based inverter 100VA capacity100VA capacity 12v DC to 220V AC inverter12v DC to 220V AC inverter Battery charging facilityBattery charging facility multivibrator based oscillator circuitmultivibrator based oscillator circuit output AC is of 55 Hz.output AC is of 55 Hz. Automatic start of inverter as soon Automatic start of inverter as soon

as power cuts as power cuts

BLOCK DIAGRAM :- BLOCK DIAGRAM :-

BLOCK DESCRIPTIONBLOCK DESCRIPTION The inverter section consists of battery charger & inverter. The inverter section consists of battery charger & inverter.

In charger section a step down transformer used to step In charger section a step down transformer used to step down the 230 v AC to 18 v AC. It is then rectified and filtered down the 230 v AC to 18 v AC. It is then rectified and filtered to give pure DC. It is passed through a regulator to give to give pure DC. It is passed through a regulator to give regulated output so that it is not change due to input regulated output so that it is not change due to input condition. Variable regulator is meant for derive 14v source condition. Variable regulator is meant for derive 14v source for charging a lead acid battery. for charging a lead acid battery.

Charger section is activated only during the AC mains Charger section is activated only during the AC mains available. During power cut inverter starts. This happens only available. During power cut inverter starts. This happens only due to a relay between battery & inverter transformer. This due to a relay between battery & inverter transformer. This relay is made ON by regulated output DC source. relay ON relay is made ON by regulated output DC source. relay ON means it cuts battery power to transformer & multivibrator means it cuts battery power to transformer & multivibrator circuit. circuit.

As soon as power cuts occurs power from regulator stops & so As soon as power cuts occurs power from regulator stops & so relay is made off. This establish bridge between battery & relay is made off. This establish bridge between battery & transformer & multivibrator section. This starts inverter action transformer & multivibrator section. This starts inverter action

INVERTER DESIGNINVERTER DESIGN Inverters circuits are in general low frequency large signal Inverters circuits are in general low frequency large signal

circuits. Therefore it is important to know the circuits. Therefore it is important to know the characteristics of the power transistors intended to be used characteristics of the power transistors intended to be used at high current levels. The gain usually falls as the current at high current levels. The gain usually falls as the current level increases and with the increase in the frequency of level increases and with the increase in the frequency of operation. The transistor dissipate a lot of heat and they operation. The transistor dissipate a lot of heat and they are therefore mounted on large heat sinks. are therefore mounted on large heat sinks.

All inverters use some kind of oscillator. Low power All inverters use some kind of oscillator. Low power inverters use a power oscillator which directly delivers the inverters use a power oscillator which directly delivers the required output power to the load. Care is taken during required output power to the load. Care is taken during design that the oscillator will start and continue to oscillate design that the oscillator will start and continue to oscillate in all practical situations of light loads and overloads. High in all practical situations of light loads and overloads. High power inverters use a low power oscillator and a power power inverters use a low power oscillator and a power amplifier to deliver requisite power. amplifier to deliver requisite power.

BASIC FUNDAMENTAL CIRCUIT BASIC FUNDAMENTAL CIRCUIT OF INVERTEROF INVERTER

In our case we have to obtain 220V Ac from 12V DC In our case we have to obtain 220V Ac from 12V DC source. Therefore a step up transformer is required. One source. Therefore a step up transformer is required. One battery is connected. Current through the winding is battery is connected. Current through the winding is oscillated. Therefore a center tapped transformer is oscillated. Therefore a center tapped transformer is required 12-0-12/ 220. Electronics switch (Transistors) are required 12-0-12/ 220. Electronics switch (Transistors) are oscillated in particular frequency therefore current flows in oscillated in particular frequency therefore current flows in first half A to B then for certain period and then for next first half A to B then for certain period and then for next period in next half of the winding C to B of the primary. This period in next half of the winding C to B of the primary. This is how a constant current is made oscillated in particular is how a constant current is made oscillated in particular frequency. So secondary winding will step up the voltage in frequency. So secondary winding will step up the voltage in the primary winding voltage to several fold to get 220V. the primary winding voltage to several fold to get 220V. During A side switch is ON, B side switch is OFF. Therefore During A side switch is ON, B side switch is OFF. Therefore output is a squasi-square wave. output is a squasi-square wave.

The switches are intermitently ON/OFF by a multivibrator or The switches are intermitently ON/OFF by a multivibrator or by logic circuit. by logic circuit.

CIRCUIT DESCRIPTION :-CIRCUIT DESCRIPTION :- The Inverter circuit in the figure consists of four main sections like The Inverter circuit in the figure consists of four main sections like Bistable multivibatorBistable multivibator Darlington pair circuitDarlington pair circuit Power transistorPower transistor RelayRelay BatteryBattery Transformer Transformer Bistable multivibrator consists of two BC547. The resistors 27kBistable multivibrator consists of two BC547. The resistors 27k and and

capacitors 0.47capacitors 0.47F are responsible for oscillation. The oscillatory F are responsible for oscillation. The oscillatory frequency is frequency is

F = 1400 / 2 (0.47 x 27) = 55 cycles / second F = 1400 / 2 (0.47 x 27) = 55 cycles / second Darlington pair circuit consists of CK100 and BD140. These two are PNP Darlington pair circuit consists of CK100 and BD140. These two are PNP

transistors responsible for giving high load current. Output of it is transistors responsible for giving high load current. Output of it is connected to the base of power transistor. Also the Darlington pair connected to the base of power transistor. Also the Darlington pair circuit is provided with pulsating signal and accordingly it inject signal circuit is provided with pulsating signal and accordingly it inject signal into power transistor base. Power transistor is power switch that is to into power transistor base. Power transistor is power switch that is to take the load current.take the load current.

Relay is SINGLE ( SPDT) one that controls power to both Relay is SINGLE ( SPDT) one that controls power to both multivibrator & inverter section. It is so connected that its coil get multivibrator & inverter section. It is so connected that its coil get regulated power from regulator. During AC available relay is ON & so regulated power from regulator. During AC available relay is ON & so it disconnect the inverter from battery. So inverter circuit is it disconnect the inverter from battery. So inverter circuit is connected to N/O ( Normally ON ) pin of the relay.connected to N/O ( Normally ON ) pin of the relay.

CIRCUIT DIAGRAM :-CIRCUIT DIAGRAM :-

MULTIVIBRATOR CIRCUIT :- MULTIVIBRATOR CIRCUIT :- Multivibrator are simply oscillators. They are fall into Multivibrator are simply oscillators. They are fall into

category of relaxation oscillator. They find wide range category of relaxation oscillator. They find wide range of application in the field of computer and electronics. of application in the field of computer and electronics.

Taking a example of LED flasher we can discuss Taking a example of LED flasher we can discuss the circuit. L1 and L2 are two flashing LEDs which are the circuit. L1 and L2 are two flashing LEDs which are connected to collector of transistor. Lamps L1 and L2 connected to collector of transistor. Lamps L1 and L2 flash alternatively. With the value of components flash alternatively. With the value of components shown L1 remains ‘on’ for approximately one second shown L1 remains ‘on’ for approximately one second L2 for next one second. L2 for next one second.

The value of on time of L1 depends upon the value of The value of on time of L1 depends upon the value of resistor R2 and the capacitor C2. By increasing the resistor R2 and the capacitor C2. By increasing the value of the R2 or C2 or both the on time of L1 can be value of the R2 or C2 or both the on time of L1 can be increased. Similarly on time of L2 depends upon the R3 increased. Similarly on time of L2 depends upon the R3 and C1. One can change the on time by varying the and C1. One can change the on time by varying the capacitor or resistor. capacitor or resistor.

MULTIVIBRATORMULTIVIBRATOR

CIRCUIT DIAGRAM :- CIRCUIT DIAGRAM :-

AC 230v is fed into the step down transformer. Transformer AC 230v is fed into the step down transformer. Transformer has input of 230v and output of 12-0-12. Then it is rectified has input of 230v and output of 12-0-12. Then it is rectified by two diodes. The rectified output is not a smooth one and by two diodes. The rectified output is not a smooth one and it is pulsating in nature, therefore it is smoothen by using a it is pulsating in nature, therefore it is smoothen by using a filter capacitor value of 1000 filter capacitor value of 1000 F. Then after this the output F. Then after this the output is a pure DC. A power supply indicator is used. For this a is a pure DC. A power supply indicator is used. For this a LED is used with series resistance. They are connected LED is used with series resistance. They are connected between +12v and the ground. between +12v and the ground.

A regulated power can be achieved by implementing a A regulated power can be achieved by implementing a regulator LM317 IC. It’s pin no. 3 is input and 2 is output. regulator LM317 IC. It’s pin no. 3 is input and 2 is output. Pin 1 is made ground through a variable resistance. Pin 1 is made ground through a variable resistance. Whenever there is any variation in voltage to pin 1 through Whenever there is any variation in voltage to pin 1 through a variable resistance, the output voltage is also varies. a variable resistance, the output voltage is also varies. Output voltage can be varied between 1.5 v DC to 12v DC. Output voltage can be varied between 1.5 v DC to 12v DC. Even if the input AC varies output remains constant. A Even if the input AC varies output remains constant. A diode is connected in series to prevent polarity reversal diode is connected in series to prevent polarity reversal during the power cut. As during power cut power from during the power cut. As during power cut power from battery may inrush into circuit. A series resistance is battery may inrush into circuit. A series resistance is connected limit the charging current , as it is safe for connected limit the charging current , as it is safe for battery as well as for regulator battery as well as for regulator

ELECTROMECHANICAL RELAYELECTROMECHANICAL RELAY The tripping device is electromechanical switch. The relay will The tripping device is electromechanical switch. The relay will

trip whenever it will receive a 12v. trip whenever it will receive a 12v. The inside construction is a simple. There is a magnetic coil The inside construction is a simple. There is a magnetic coil

on plastic & magnetic material. Copper wire is wound on it. on plastic & magnetic material. Copper wire is wound on it. The wire used is very thin having a resistance 200The wire used is very thin having a resistance 200. It is . It is hinged on a iron frame at one side. An iron plate is coated hinged on a iron frame at one side. An iron plate is coated and copper contact is set. The contact point is always set and copper contact is set. The contact point is always set between two contact points A & B. The one side of the plastic between two contact points A & B. The one side of the plastic is always attached by a spring S with iron frame, that its is always attached by a spring S with iron frame, that its contact point remain contact with upper contact point with A. contact point remain contact with upper contact point with A. There is a plastic plate set on the iron frame to hold contacts. There is a plastic plate set on the iron frame to hold contacts. There are two contacts. There are two contacts for two coil There are two contacts. There are two contacts for two coil sides. The contact pin for A, B contact point and there is sides. The contact pin for A, B contact point and there is another point which is connected to load contact(movable). another point which is connected to load contact(movable). The moving contact helps in changing taps in auto-The moving contact helps in changing taps in auto-transformer. As takes load current it is made thicker. transformer. As takes load current it is made thicker.

Electromagnetic force is produced by the magnetic flux, Electromagnetic force is produced by the magnetic flux, which is produced by the operating quantity. The which is produced by the operating quantity. The electromagnetic force exerted on the moving element, is electromagnetic force exerted on the moving element, is proportional to the square of the flux in the air gap or the proportional to the square of the flux in the air gap or the square of the current. square of the current.

Fig.. internal structure of the tripping device.

LM317LM317 LM317 3-teminal adjustable voltage LM317 3-teminal adjustable voltage

regulators It is adjustable positive voltage regulators It is adjustable positive voltage regulators capable of supplying in excess regulators capable of supplying in excess of 1.5A over a 1.2v to 37v output range . of 1.5A over a 1.2v to 37v output range . They are exceptionally easy to use and They are exceptionally easy to use and require only two external resistor to set require only two external resistor to set the output voltage . Further both line and the output voltage . Further both line and load regulation are better than standard load regulation are better than standard fixed regulators . Also the LM317 is fixed regulators . Also the LM317 is packaged in standard transistor packages packaged in standard transistor packages which are easily mounted and handled .which are easily mounted and handled .

FEATURES :FEATURES :

Adjustable output down to 1.2 vAdjustable output down to 1.2 v Guaranteed 1.5v output current Guaranteed 1.5v output current line regulation typically 0.1%line regulation typically 0.1% load regulation typically 0.1%load regulation typically 0.1% current limiting constant with temperaturecurrent limiting constant with temperature 100% electrical burn-in 100% electrical burn-in eliminates the need to stock many eliminates the need to stock many

voltagesvoltages standard 3-lead transistor package standard 3-lead transistor package 80dB ripple rejection 80dB ripple rejection

DARLINGTON CIRCUIT:-DARLINGTON CIRCUIT:- If two transistors of the same type are directly If two transistors of the same type are directly

connected as shown. The emitter of T1 is connected connected as shown. The emitter of T1 is connected to base of T2, the combination has a total of three to base of T2, the combination has a total of three external connections B, C and E and act as a single external connections B, C and E and act as a single transistor whose gain equals the T1 gain x the T2 transistor whose gain equals the T1 gain x the T2 gain. In order to handle greater load current T1 gain. In order to handle greater load current T1 may be connected to two or more than two may be connected to two or more than two transistors in parallel. The Re resistors help to transistors in parallel. The Re resistors help to equalize the load current.equalize the load current.

USES :-USES :- Inverter is power converter of DC to AC. It Inverter is power converter of DC to AC. It

can be used as emergency power supply can be used as emergency power supply unit. Using inverter we can obtain a unit. Using inverter we can obtain a various frequency of AC signal. That can various frequency of AC signal. That can be used in laboratory for other be used in laboratory for other applications. Home appliances like t.v. applications. Home appliances like t.v. sets, radios kitchen appliances and the sets, radios kitchen appliances and the like in cottage boat or trailer. In aircraft it like in cottage boat or trailer. In aircraft it may supply power at relatively high may supply power at relatively high frequencies of say 400 or 1000 Hertz. frequencies of say 400 or 1000 Hertz. During power failure inverter is the During power failure inverter is the essential item that supply power.essential item that supply power.

CONCLUSION: -CONCLUSION: - This inverter is done from project This inverter is done from project

point of view. This is low wattage for point of view. This is low wattage for demonstration purpose and studying demonstration purpose and studying the output waveform. The oscillator the output waveform. The oscillator circuit is very good from project point circuit is very good from project point of view. This project as a crude of view. This project as a crude power supply unit and can be used in power supply unit and can be used in home. Within 80 watt load can be home. Within 80 watt load can be used in output.used in output.

THANKYOUTHANKYOU