Scr Switching Regulation/Ac Regulator Built In Type - Honda Motorcycle Service Manual

BATTERIESICHARGINGILlGHTlNG SYSTEM
(Battery1
This method is similar to the method explained previously
except that the voltage regulation is done after the signal is
converted to DC at the input of the battery. Since this method
regulates output voltage of alternator after it is rectified, its
charging is precisely controlled.
In order to regulate the current going to the headlight, there is
sometimes a resistor connected to the ground wire of the
regulatorlrectifier through a switch. Since the charging coil
powers the headlight as well, the headlight flickers and dims
when the output of the charging coil is shorted to ground
through the SCR. This happens because when the ground
wire of the regulatorhectifier is connected to ground, the
resistance AB becomes less than AC, so less current is
diverted to the headlight. In order to keep current flowing to
the headlight steadily, a resistor, whose value is greater than
resistance between AC, is placed between AD.
(SCR switching regulation1AC regulator built in type)
This regulation method is used for models with small
displacement engines. Unlike the type above, the SCR is used
for switching and the ZD (zener diode) is used for voltage
regulation.
The regulator may overcharge the battery if the ground wire is
broken or if there are poor connections at the terminals.
The output of the alternator goes to the gate of SCRl via the
22-18
Date of Issue: March, 1995
0
HONDA MOTOR CO..LTD.
DC voltage regulator. When the voltage at the cathode of
SCRl is.less than the voltage at the gate, the thyristor turns
ON and conducts current to the battery. When AC output of
the alternator changes from positive to negative, the gate
voltage of SCRl becomes zero, turning OFF the thyristor and
cuning off the negative signal to the battery.
The output voltage is regulated by ZD1 and ZD2 which turn
ON (and short to ground) when the output voltage of the
charging coil increases beyond a specified value. When the
ZDs turn ON, the SCRl turn OFF by reducing the gate
voltage of thyristor and causes the output voltage regulated.
CATHODE
ALTERNATOR
ANODE
ALTERNAT