３ INTERNAL CONNECTION
ＭＵＸ-１００ SERVICE MANUAL
３ - ６
３-２-４ Charging circuit
Related PCB: MUX POWER PCB, MUX CHARGE-04A/04B PCB
Ⅰ
Charging
ⅰ
When the power plug is connected, the 125V (125F-0F) output of the transformer T1 is input to the connector
JT1A on the MUX CHARGE-04B PCB.
ⅱ
The above mentioned 125V is rectified and charged on the capacitor C6,then this charged voltage on C6
(about 177
±
20V) is connected to the inverter circuit on the MUX CHARGE-04B PCB.
The output of this inverter circuit is connected to the battery via the connector JSC3 on the MUX POWER
PCB.
ⅲ
This inverter circuit on the MUX CHARGE-04B PCB is controlled by the driving signal Q14C/Q23C from
MUX POWER-04A PCB via the connector JCH3.
The MUX CHARGE-04A PCB controls the inverter by PWM method while comparing the measured
charging current IC1 (CP9:1V/1A) with the preset charging current PIC (CP25:1V/1A).
The measured charging current is detected by the current transformer CT1 on the MUX CHARGE-04B
PCB .
ⅳ
The preset charging current PIC is controlled as the following table depending on the current charged
voltage of the battery.
Beginning of charging
Charging starts with PIC 0.5A..
If the charged voltage doesn’t reach to 280V
within 5 min., proceeds to STEP 1.
If the charged voltage reaches to 280V within 5
min., proceeds to STEP 3.
STEP 1
PIC is 2.0A. Proceeds to STEP 2 when the
charged voltage reaches to 280V.
STEP 2
PIC is 1.0A. Proceeds to STEP 3 when the
charged voltage reaches to 285V.
STEP 3
PIC is 0.4A. Proceeds to STEP 4 when the
charged voltage reaches to 290V.
STEP 4
PIC is 0.18A. Charging finishes when the
charged voltage reaches to 290V.
Table 3.1 STEP of PIC
As well, there are two kinds of switching frequency of the inverter for battery charging depending on the
preset charging current PIC as shown on the below table.
PIC
Frequency of the inverter
2.0A
1.0A
13kHz
0.4A
0.18A
2kHz
Table 3.2 Frequency of the inverter for battery charging
