THE IGNITION SYSTEM
-Provides a method of turning a spark ignition engine on & off. -Operates on various supply voltages (Battery & Alternator) -Distributes spark to each plug in correct sequence.
PARTS - provides power for system.
- allows driver to turn ignition on/off.
- changes battery voltage to 30,000V during normal operation and has a potential to produce up to 60,000V. 11/20/2018
- distributes the spark to the spark plugs in the correct sequence and at the correct time.
- an electr electrical ical devi device ce used used to initiate combustion by creating a high voltage discharge across an electrode
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Distributor Cap - An insulated insulated plastic plastic cap cap that transfe transfers rs voltage voltage from coil (wire) to Rotor. Distributor Rotor - Tran Transfers sfers voltage voltage from the the distributo distributorr cap center center terminal (coil) to distributor cap outer terminals (spark plugs). Ignition control module - An electro electronic nic switch switch that that turns turns the the ignition coil primary current on/off
THREE TYPES OF VEHICLE IGNITION SYSTEMS AND HOW THEY WORK
THE DISTRIB DISTRIBUT UTOR OR AUTOMOTIVE AUT OMOTIVE IGNITI IGNITION ON SYSTEM
Connects to the camshaft with gears. Inside, a set of “ignition of “ignition points” points” rubs against a multi-sided cam on the distributor shaft. The cam opens and closes the points. Once the coil gene ge nera rattes fi firi ring ng vo volt ltag age, e, it tr trav avel els s to the top of the coil and into the top of the th e di dist stri ribu buto torr ca cap. p. Th The ere re,, a ro rottat atiing disc di sc at atttac ache hed d to th the e di dist stri ribu buto torr sh shaf aftt “distributes” the “distributes” the power to each of the spark plug wires.
THE DISTRIBUTOR-LESS AUTOMOTIVE IGNITION SYSTEM (DIS)
This system determines spark timing based on two shaft position sensors and a computer.
The Crankshaft Position Sensor (CKP) is mounted at the front of the crankshaft, or near the flywheel on some vehicles.
The Camshaft Position Sensor (CMP) is mounted near the end of the camshaft. These sensors continually monitor both shafts’ positions and feed that information into a computer.
COIL-ON-PLUG IGNITION SYSTEM
Incorporates all the electronic controls found in a DIS car ignition system.
Some COP car ignition systems generate as much as 40,000 to 50,000 volts and much hotter, stronger sparks.
BASIC CIRCUITRY Ignition systems have a primary(low-voltage) circuit to connect and disconnect the ignition coil and the secondary(high-voltage) circuit to send voltage from the battery to the spark plug.
The amount of high voltage induced depends on the speed of change in the magnetic field, the number of windings on the secondary coil, and the strength of the magnetic field. The opening induction voltage of the primary winding is between 300 and 400 V.
The high voltage on the secondary can be up to 40 kV, kV, depending depend ing on the ignition coil.
And
of Ignition system
Do
not touch or remove ignition cables, the distributor cap, or the spark plug connectors when the engine is running.
Only
connect or disconnect electronic control units, plug connections, and connection cables when the ignition is switched off.
Only
wash the engine when the engine is at a standstill and the ignition is switched off.
During
all tests on the ignition system that require the engine to turn over at starter speed, the voltage supply to the injection valves should be interrupted in order to protect the catalytic converter.
THE STARTING AND CHARGING SYSTEM
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COMPONENTS AND FUNCTIONS OF CHARGING SYSTEM
1. Battery The function of the battery is as a storage of electricall energy electrica energy.. 2. Fuse and Fusible links Fuse and fusible links have different functions functions even though have the same shape. Fusible link can be called as main fuse which is placed near the battery positive terminal. The function of this fuse is to protect the entire electrical system of the car from excessive currents. 3. CHG Lights CHG lamp or commonly also called “charging warning light” is an indicator light to indicate the presence failure of charging system.
4. Ignition key The ignition key works as a switch. The charging system will be activated automatically when the engine is running, but to generate a magnetic field on the rotor coil must be done by a switch. 5. Regulator The function of the regulator is to regulate the voltage generated by the alternator.
6. Alternator The function of the alternator is to convert a partial engine's rotating energy into electric e lectricity ity.. 7. Charging Wires The function of charging wires are to connect every component of the charging system, there are at least two types of wires: standard wire and B + wire
COMPONENTS AND FUNCTIONS OF STARTING SYSTEM
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1) The "starting system", the heart of the electrical system in your car, begins with the BATTERY BATTERY.. 2) The key is inserted into the IGNITION SWITCH and then turned to the start position 3) A small amount of current then passes through the NEUTRAL SAFETY SWITCH to a STARTER RELAY which allows high current to flow through the BATTERY CABLES to the STARTER MOTOR. 4) The starter motor then cranks the engine so that the piston, moving downward, can create a suction that will draw a Fuel/Air mixture into the cylinder, where a spark created by the IGNITION SYSTEM will ignite this mixture. 5) If the Compression in the engine is high enough and all this happens at the right Time, the engine will start.
Ignition Switch
The ignition switch allo al lows ws th the e driv driver er to to distribute electrical current to where it is needed.
5 key switch positions that are used: 1. Lo Lock ck-- All circuits are open ( no current supplied) and the steering wheel is in the lock position. In some cars, the transmission lever cannot be moved in this position. If the steering wheel is applying pressure to the locking mechanism, the key might be hard to turn. If you do experience this type of condition, try moving the steering wheel to remove the pressure as you turn the key. 2. Off - All circuits are open, but the steering wheel can be turned and the key cannot be extracted. 3. Run- All circuits, except the starter circuit, are closed (current is allowed to pass through through). ). Current is supplied to all but the starter circuit.
4. StartStart- Power is supplied to the ignition circuit and the starter motor only. That is why the radio stops playing in the start position. This position of the ignition switch is spring loaded so that the starter is not engaged while the engine is running. This position is used momentarily momentari ly,, just jus t to activate the starter st arter.. 5. AccessoryAccessory- Power is supplied to all but the ignition and starter circuit. This allows you to play the radio, work the power windows, etc. while the engine is not running.
Most ignition switches are mounted on the steering column. Some switches are actually two separate parts
The lock into which you insert the key. This component also contains the mechanism to lock the steering wheel and shifter. The switch which contains the actual electrical circuits. It is usually mounted on top of the steering column just behind the dash and is connected to the lock by a linkage or rod
BASIC PARTS OF DC MOTORS
ARMATURE (AXLE,ROTOR)
The armature interacts with the magnetic field (magnetic flux) in the airgap; the field component can comprise either permanent magnets, or electromagnets formed by a conducting coil such as another armature
STATOR
The stator is the stationary part of a rotary system, found in electric generators, electric motors, sirens, mud motors or biological rotors. Energy flows through a stator to or from the rotating component of the system
COMMUTATOR
A commutator is a rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit. It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine.
FIELD MAGNETS (FIELD COIL)
A field coil is an electromagnet used to generate a magnetic field in an electromagnetic machine, typically a rotating electrical machine such as a motor or generator. It consists of a coil of wire through which a current flows
BRUSHES
A brush or carbon brush is a device which conducts current between stationary wires and moving parts, most commonly in a rotating shaft. Typical applications include electric motors, alte al tern rnat ator orss an and d el elec ectr tric ic ge gene nera rattor ors. s.
3 TYPES OF STARTER MOTOR IN TODAY’S VEHICLES
INERTIA
Inertia starters work by rotating a pinion and moving it forward through centrifugal force towards the ring-gear. As it continues to spin, the teeth of the pinion lock into the ring-gear and crank the engine.
PRE ENGAGED
The pre-engaged starter motor is employed for highcompression engines with automatic transmission system such as large petrol engines and small diesel engines. When the ignition is switched on and the starter switch is closed, current from the battery flows to the solenoid windings generating a magnetic field. When the pinion is fully engaged, the solenoid contacts are closed, so that current flows from the battery to energize the starter field and armature windings. The armature shaft then rotates and cran cr anks ks th the e en engi gine ne
GEAR REDUCTION
The Chrysler gear-reduction starter formed the conceptual basis for the gear-reduction starters that now predominate in vehicles on the road. Light aircraft engines also made extensive use of this kind of starter, because its light weight offered an advantage.
Basic AC Motor Oper Operation ation An AC motor has two basic electrical parts: a "stator" and a "rotor".
The
stator is in the stationary electrical component. It consists of a group of individual electro-magnets arranged in such a way that they form a hollow cylinder, with one pole of each magnet facing toward the center of the group. The term, "stator" is derived from the word stationary. The stator then is the stationary part of the AC motor.
The rotor is the rotating electrical component. It also consists of a group of electro-magnets arranged around a cylinder, with the poles facing toward the stator poles. The rotor is located inside the stator and is mounted on the AC motor's shaft. The term "rotor" is derived from the word rotating. The rotor then is the rotating part of the AC motor.
THRE TH REEE- PH PHAS ASE E AC MOT MOTOR
A threephase induction motor runs on a three phase AC supply. Threephase induction motors are extensively used for vari va riou ouss in ind dus ustr tria iall ap appl plic icat atio ions ns be beca cau use of their following advantages
They have very simple and rugged (almost unbreakable) construction
They are very reliable and having low cost co st
They have high efficiency and good power factor f actor
Minimum maintenance required
3 phase induction induction motor is self starting starting hence extra extra starting starting motor or any special starting arrangement is not required
They also have some disadvantages
Speed decreases with increase in load, just just like a DC shunt motor
If speed is to be varied, we have sacrifice some of its efficiency
3 COMPONENTS OF CHARGING SYSTEM
The
alternator generates electrical power to run accessories and to recharge the batteries. It is normally driven by a belt located off the crankshaft. Mechanical energy from the crankshaft is converted by the alternator into electrical energy for the batteries and accessories.
The voltage regulator acts as an electrical traffic cop to control alternator output. It senses when the batteries need recharging, or when the vehicle’s electrical needs increase, and adjust the alternator’s output accordingly.
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The batteries are a reservoir of chemical electrical power. Their primary purpose is to crank the engine. They also supply power to vehicle accessories when the electrical load is too great for the alternator alone.
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MAJOR PARTS OF AN AC GENERATOR
Rotor
The rotor assembly consists of drive shaft, coil, and two pole pieces. A pulley mounted on one end of the shaft allows the rotor to be spun by a belt driven by the crankshaft pulley. The rotor is a rotating magnetic field insi in side de th the e al alte tern rnat ator or..
Stator
The
stator is the stationary member of the generator.
The
rotor rotates inside the stator stat or.. A small air a ir gap between the two allows the rotor to turn without making contact with the stator.
Slip rings and brushes
Conduct Current
current to the spinning rotor.
is transmitted from the field terminal of the brush and slip ring to the field coil. Current passes through the field coil and the second slip ring and brush bef in d
Cooling fans
This cooling fan draws air into the housing through the openings at the rear of the housing. the moving air pulls heat from the diodes and their heat he at de decr crea ease ses. s.
Do’s and Don’ts of the System
Disconnect
the battery ground cable before removing any leads from the systems. Do not reconnect the battery ground cable until all wiring connections connections have been made.
Avoid
contact with the AC generator output terminal. This terminal is hot (has voltage present) at all times when the battery cables are connected.
The
AC generator is not made to withstand a lot of force. Only the front housing is relatively strong. When adjusting belt tension, apply pressure only to the front housing to avoid damaging the stator and rectifier.
Keep the tester’s carbon pile off at all times,
except during actual procedures.
test
When installing a battery, be careful to observe the correct polarity. Reversing the cables destroys the diodes. Proper polarity must also be observed when connecting a booster battery, positive to positive and negative to ground. 11/20/2018
