M-27
WG972-E2, DF972-E2, WSM
GASOLINE / LPG ENGINE
3. In Charging
Because BATT terminal voltage just after engine start
is lower than setting value (14 to 15 V), or lower than
zener level of
Z1
, current is not supplied to base of
Q4
and
Q4
is off, as shown in figure
(B)
.
Q3
is on with base
current which flows thorugh the route of BATT
→
emitter
/ base of
Q3
→
R2
→
D6
→
BATT, and gate current is
supplied to
S1
or
S2
through the route of GEN
→
D1
→
emitter / collector of
Q3
→
R3
→
gate / cathode of
S2
→
GEN, or GEN
→
D2
emitter / collector of
Q3
→
R3
→
gate / cathode of
S1
→
GEN.
When engine speed is increased so that GEN
genetration voltage becomes higher than BATT terminal
voltage,
S1
or
S2
is turned on and, as shown in figure
(C)
, charge current is supplied to BATT through the route
of GEN
→
D1
→
BATT
→
anode / cathode of
S2
→
GEN,
or GEN
→
D2
→
BATT
→
anode / cathode of
S1
→
GEN.
After
S1
or
S2
is turned on, collector current of
Q1
and
base current of
Q3
are supplied by GEN, not BATT.
When key switch is turned to position 1 after engine is
started, BATT is charged, if BATT terminal voltage is
lower than the setting value, or zener level of
Z1
.
W1035755
4. Over-Charge Protection
When BATT terminal voltage is higher than the
setting value or zener level of
Z1
, BATT is not charged
by the function of circuit as shown in figure
(D)
. That is,
Q4
is on with base current which flows through the route
of BATT
→
emitter / base of
Q4
→
Z1
→
D6
→
BATT,
shortcircuiting emitter and base of
Q3
. Therefore,
Q3
is
off with no base current and gate current is not supplied
to
S1
and
S2
. Consequently
S1
and
S2
are off and BATT
is not charged.
W1036458
KiSC issued 01, 2006 A