Kubota B1830, Workshop Manual

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ELECTRICAL SYSTEM B1830,B2230,B2530,B3030, WSM
9-M21
[1] ALTERNATOR
A compact alternator with an IC regulator is used,
having the following characteristics:
• Approximately 26 % lighter and 17 % smaller than a
standard alternator.
• Cooling performance and safety have been
improved by combining the cooling fan with the rotor
and incorporating the fan / rotor unit inside the
alternator.
• IC regulator is fitted inside the alternator.
• The rectifier, IC regulator and similar components
are easy to remove, making it easier to service the
alternator.
9Y1210003ELM0016US0
[2] IC REGULATOR
An IC regulator uses solid state transistors, chips or other semiconductor elements instead of the relays in a
conventional regulator. Stable characteristics are achieved by cutting off the field current.
IC regulators have the following characteristics:
• The control voltage does not change over time, so the need for readjustment is eliminated. Since there are no
moving parts, IC regulators are extremely durable and resistant to vibration.
• The overheat compensation characteristics ensure that the control voltage is reduced as the temperature rises,
so the battery is charged at just the right level.
The internal circuitry of the IC regulator is shown in the diagram. It consists of a hybrid IC incorporating a
monolithic IC. (The internal circuitry of the monolithic IC is extremely complex, so it is shown as simply "M.IC circuit" .)
Tr1 acts as the contacts controlling the field current, and Tr2 acts as the charge lamp relay controlling the flashing
of the charge lamp.
The M.IC circuit controls Tr1 and Tr2 , and monitors the alternator output voltage, and detects any drop in L
terminal voltage or breaks in the rotor coil.
9Y1210003ELM0017US0
(1) Stator
(2) Rotor
(3) Rectifier (4) IC Regulator
(5) Brush Holder
(1) Alternator
(2) Rectifier
(3) Stator Coil
(4) Rotor Coil
(5) IC Regulator
(6) Charge Lamp
(7) Main Switch
(8) Battery
(9) Load
KiSC issued 05, 2012 A