３ INTERNAL CONNECTION
ＭＵＸ-１００ SERVICE MANUAL
３ - ５
３-２-２ Operation when power plug is connected (changeover between AC and DC of DC pack input)
Related PCB: MUX POWER PCB
ⅰ
When the power plug is connected, the 100V output (100E-0E) of the transformer T1 is input to the
MUX POWER via the connector JT1C.
ⅱ
The relay K1 turns ON, and the power supply line to the DC pack is changed over from the battery
power to the 100 VAC.
ⅲ
100 VAC is supplied to the DC pack, 5V, 15V and 24V are output from the DC pack, and the control
PCB starts to operate.
ⅳ
At the same time with ii, the relays K3 and K2 turn ON. When the K3 turns ON, connection of the
relays K6 and K7 to the coil is shut down, and the batteries are isolated from all loads.
ⅴ
When the relay K2 turns ON, the ACON1 and the ACON2 are short-circuited, connection of the power
plug is transmitted (as the LVON signal) to the XCONT PCB via the MUX CHARGE-04A PCB, then
the CPU recognizes connection of the power plug.
(Reference) Based on the lesson learn from the MC125L-50, all loads are isolated while the batteries are
charged. The used DC pack is the 110-330 VDC/90-264 VAC input type.
３-２-３ Detection of battery voltage
Related PCBs: MUX POWER PCB and MUX CHARGE-04A PCB
Ⅰ
Explanation
ⅰ
Twenty batteries are connected in series, 10 batteries on the pulse side and 10 batteries on the minus
side.
The middle point is connected to the chassis via resistors of several M
Ω
(on the MUX POWER, MUX
CHARGE-04A and MU DRIVER PCBs).
ⅱ
The plus, the minus and the middle point of the batteries are offered at the following terminals on the
MUX POWER PCB.
Battery plus side
: TER1 [B120+]
Battery middle point : TER5 [B0]
Battery minus side : TER2 [B120-]
ⅲ
The values at the terminals above are converted into the battery voltage detection value (“120+” signal at
CP10 and “120-” signal at CP11) on the MUX CHARGE-04A PCB via the resistors R8 to R11 (10
M
Ω
) and the connector JBV1.
The relationship between the actual battery voltage and the detection value (“120+” and “120-” signals)
is approximately “3V/100V”. For example, when the actual battery voltage is 120V, the detection
value at CP10 or CP11 is about 3.6V.
ⅳ
Finally, the “120+” and “120-” signals are sent as the VP1 and the VP2 to the XCONT PCB.
Ⅱ
Battery Charged Voltage Over
ⅰ
The “120+” and “120-” signals are checked for the error Charged Voltage Over by the operation
amplifier A8.
The threshold is 4.67V.
It is equal to 156V (= 4.67
×
100/3) as the actual battery voltage (on both plus and minus sides).
ⅱ
The detection result is sent as the error signal CHBR2 to the XCONT PCB, then charging stops.
(Reference) The connectors JB60 and JBV2 on the MUX POWER PCB are not used.
