Veichi AC310 Service Manual page 46

This module is mainly used for shaping the seven drive signals from the CPU and
enhancing the drive capability of the drive signals to provide suitable drive waves for the IGBT
module. In the event of a fault, the CLOSE signal output from the hardware blocking circuit
of the system fault becomes high, resulting in no output from the drive signal processing circuit,
which leads to blocking of the drive and protection of the machine.
2. Type of fault
UVW no output (driver board normal), output phase loss, output unbalance
3. Inspection Methods
After powering on, measure whether the given voltages (3.3V and 5V) on both sides of
the chip are normal, especially whether there is 5V on pin 20 of the chip; measure the change
of the CLOSE signal, when there is a fault, the CLOSE signal output from the system fault
hardware blocking circuit becomes high level.
Corresponding voltage when not in operation (DC phase)
UH UL
GND
5V 5V
Waveforms of one of the drive signals and GND outputs during operation: as
follows (if the output waveforms are abnormal, the control board is abnormal)
Measured in AC mode during operation, the voltage of each drive signal and GND is
about 11.5v.
4. Device bit number and specification
Resistances
R137/R138/R139/R140/R141/R189=4.7K/0402
R131/R132/R133/R134/R135/R190
IC U10=SN74ACT244PWR
VH VL
5V 5V
AC310 Universal AC Drive Service Manual
WH WL
5V 5V
Capacitors
C70=2.2UF/0402
C71=100NF/0402 C75=100P
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