Alternator Terms
Regulator voltage test
13.5 to 14.5 Checks calibration and high/low voltage. Most regulators
Stator Assembly
3 Stator windings or coils, stator core and output wires.
Zener diode
Allows current to flow in either direction when it hits a certain voltage.
Regulator bypass test
Alternator, Regulator, or circuit is faulty. Regulator is taken out of circuit.
Charge Indicator
Indicates charging system status Types Warning light Voltmeter indicator Ammeter indicator
Alternator drive belt
Links crankshaft pulley to alternator pulley.
Output test
Measures under load. Check with load tester.
Brush assembly
Brush housing, brushes, brush springs and brush wires.
Rectifier Diodes
Mounted in a diode frome or heat sink (metal mount for removing excess heat from electronic parts) 3 positive diodes are press fit in an insulated frame, and 3 negative diodes are mounted in an uninsulated or grounded frame
Alternator Slip rings
Mounted on the rotor shaft to provide current to the rotor windings. Each end of the field coil connects to one of the slip rings. An external source of electricity is need to excte the field.
Alternator Bearings
Needle or ball types. commonly used to produce a low friction surface for the rotor shaft. These bearings support the rotor and shaft as they spin inside the stator. . Front bearing is frequently held in place with small plate and screws. Rear bearing is usually press fit into place.
Diode service
Ohmmeter Special diode test Ohmmeter diode test (most common)
Transistors
Performs the same basic function as a relay. can turn circuits on and off more than 200 times a second (electronic switch.)
Rotor Field windings
Produces magnetic field in the machine.
Alternator terminals
Provides output place
Alternator Brushes
Ride on the slip rings to make a sliding electrical connection. Brushes feed battery current into the slip rings and rotor windings. current flow into the rotor winding is low.
Rotor
Roatating electromagnet. Spins inside the stator electromagnetic field. Produces magnetism.pole finger/claw poles (intensifies magnetic field. field windings slip rings
Brush Springs
Small, Hold the brushes in contact with the slip rings.
Regulator service
Some regulators Turn screw to adjust Run engine at idle
Stator
Stationary closed conductor. Inside alternator ectromagnetic field that has wire coils on each sides collects spinning motion. Consists of 3 groups of windings. Windings are wrapped around a soft, laminated iron core or ring. The stator produces electrical output of the alternator. Iron core is used to concentrate and stregthen the field around the stator windings.
voltage regulator
Controls alternator output by changing the amount of current flowing through the rotor windings. Any change in rotor winding current changes in this way, the voltage regulator can maintain a preset charging voltage. May be integral or mounted in vehicles computer.
Belt types
Conventional V-Belt Cogged V-Belt Ribbed Belt
Alternator
Converts mechanical energy to electrical energy. Produces electricity and charges battery. Rectifies (changes) alternating current to direct current. Provides electricity to vehicle systems after engine start.
Bearing Service
Grinding noise Commonly replaced during build Check and service as required
Voltmeter test of system
Used to test chargin system output when a load tester is not available. Measures charging system voltage with all electrical accessories on.
Electronic voltage regulator
Uses an electronic circuit (transistors,diodes,resistors and capacitors. to control rotor field strength and alternator output. Electronic voltage regulator is a sealed unit and cannot be repaired. Must be sealed because it can be damged by moisture,excessive heat and vibration. Usually circuit is surrounded by a rubber like gel for protection.
Electromagnetic Induction
Uses magnetism to produce electricity.(How alternator produces electricity) Current is induced into the conductor when the conductor is moved at right angles across a magnetic field. Magnetic field stregthens when several electricity carrying wires are placed next to each other. Inserting an iron core through the coils stregthens the field further.
Rotor service
Visually inspect Short to ground test Open circuit test Current test
Y-Type stator
Wire ends from the stator windings connected to a neutral junction. Provides good current output at low engine speeds.
Circuit resistance test
Wiring system problems. Other than alternator regualtor Common tests are insulated and ground circuit resistance test.
Integral voltage regulator
electronic regulator comprised of integrated circuits and mounted inside or on the rear of the alternator. It is the most common type. Small, efficient and dependable.
Delta- Type Stator
has stator wires connected ened to end with no neutral junction, two circuit paths are formed between diodes during each phase. used in high- output alternators.
Diode Trio
used to supply current to the rotor field windings.3 diodes are mounted in a single unit one end connected to rectifier bridge. Used to feed current through the elctronic regulator. The stator output feeds it.
Rectifier Bridge
(Diode assembly) Changes AC to DC 6 diodes 3 positive 3 negative
Stator service
(Ohmmeter) Visually inspect Check for open ground
Full-Wave rectification
(changes both positive and negative outputs into direct current) as the different polarity rotor claws pass the stator windings.
Common Problems
Dead batter, overcharged battery, abnormal noises, indicator problem. verify by starting engine
Rectifier assembly
Diodes, heat sink or diode plate and brush wires.
Removal of alternator
Disconnect battery Loosen bolt/ remove belt Disconnect wires and remove.
Housing
Drive end frame, slip ring end frame and end frame bolts
Battery
Energizes the alternator and stabilizes alternator output. SUpplies power during cranking. With engine running charging system provides current.
Rotor assembly
Field windings, claw poles, rotor shaft and slip rings.
System scope test
analyzes alternator voltage waveform for signs of abnormal ripple.
