Ic Regulator - Kubota M6800S Workshop Manual

M6800 · M6800S · M8200 · M9000, WSM

[1] IC REGULATOR

(1) Alternator
(2) Stator Coil
(3) Field Coil
1. When the main switch (8) is turned on, the base current of the power transistor starts flowing.
Battery → Main Switch (8) → Terminal (R) → Power Transistor's (5) Base → Power Transistor's (5) Emitter →
Ground.
2. Now the power transistor (5) is energized, causing the field current to flow.
Battery → Main Switch (8) → Charge Lamp (7) – Terminal (L) · Resistance R
(5) → Ground.
3. The engine gets started and the alternator starts generating electricity. The base current and field current,
mentioned above, are both supplied by the alternator. The field current flows as follows.
Trio Diode (4) → Field Coil (3) → Power Transistor (5) → Ground.
4. If the alternator-generated voltage is too low, the terminal voltage (divided by resistors R
at point "a") of the Zener diode D
D and that the transistor Tr
Z
5. In this state, the generated voltage gets higher. When the voltage applied to the Zener diode D
voltage, current starts flowing into the diode D
Terminal (L) → Resistor R
Ground.
6. Now the transistor Tr
1
circuit between the base and emitter of the power transistor (5). The base current of the power transistor stops
flowing, causing the power transistor (5) to turn off. The field current is therefore cut off, reducing the generated
voltage.
7. In this way, the voltage begin applied to the Zener diode D
then the transistor Tr
1
(5) again. This transistor is energized to make the field current and raise the generated voltage. The above steps
5., 6., 7. are repeated to turn on and off the field current and control the alternator voltage.
8. The capacitor C is intended to keep the transistor Tr
and surges at ignition are suppressed. The reverse-current preventive diode D
would flow from the trio diode through terminal L to the machine's cabling.
(4) Trio Diode
(5) Power Transistor
is lower than the Zener voltage. This means that no current flows into the diode
Z
is shut off.
1
. This current is the base current of transistor Tr
Z
→ Point "a" → Diode D
V
is energized. In this state, the collector and emitter of transistor Tr
are therefore turned off again. This causes the base current to flow in the power transistor
(6) IC Regulator
(7) Charge Lamp
6
→ Base of Transistor Tr
Z
drops below the Zener voltage. The diode D
Z
functioning stably. To do this, repples of the alternator output
1
9-M19
ELECTRICAL SYSTEM
(8) Main Switch
(9) Battery
→ Field Coil (3) → Power Transistor
and R , electric potential
V 1
exceeds the Zener
Z
.
1
→ Emitter of Transistor Tr
1
makes a sort of short-
1
serves to block the current that
6
KiSC issued 03, 2008 A
→
1
first and
Z