User and Programming Manual - Rev H
California Instruments
P Series
May 2000
21
5.3 Power Factor Correction Module (PFC)
The P.F.C consists of an input EMI filter, input bridge and boost converter. The boost converter
is PWM controlled by a single chip that adjusts the pulse width during the cycle so that only
sine wave current is drawn from the supply. An auxiliary winding on the boost inductor provides
“bootstrap” power to the logic circuits and is self sustaining.
5.4 DC - DC Converter Module
The 385 VDC from the boost converter is fed to the DC to DC module. It first supplies 385 volts
DC to the auxiliary power supply. When the auxiliary power supply starts it, it supplies 6
isolated DC supplies to the AC module. It also supplies 15 volts to the DC converter on the
same DC module. The DC to DC converter will then start operating. The DC converter supplies
either 250 volts DC or 400 volts DC to the DC to AC module.
The DC to DC converter is a full bridge converter and the auxiliary converter is a two FET
forward converter.
All the 8 LEDs on the DC-DC board should be lit under normal operation. The LED DS200 is lit
when the DC output is up and within regulation. The amber LEDs DS5, DS4 and DS3 indicate
that the 15V power to the optocouplers on the AC converters is within regulation. The red and
green LED’s, DS7 and DS6 indicate logic power to the AC converter is ok. The red LED DS8
indicates that logic power to the DC converter is within specification at 15 volts. The LED DS2
shows that 24 volt fan power is available.
Table 1: Logic Board Led's
LED#
FUNCTION
COMMENTS
DS2
24V ok
24 volt fan power is available.
DS3
15V ok
15V power to the optocuplers on the AC converters is within
regulation
DS4
15V ok
15V power to the optocuplers on the AC converters is within
regulation
DS5
15V ok
15V power to the optocuplers on the AC converters is within
regulation
DS6
power ok
logic power is ok to the AC converter
DS7
power ok
logic power is ok to the AC converter
DS8
power ok
logic power is ok to the DC converter
DS200
DC bus ok
DC output is up and within regulation
