California Instruments 2001RP, User And Programming Manual

Page: 49 / 130

User and Programming Manual - Rev N
5.4 Range Relay Board
The Range Relay Board, Module Assembly A2, has all of the AC Power Source relays.
These relays are operated from +50 VDC. The output relay is controlled by the CNF Logic
Line. The range relay is controlled by the LVR line.
There is a current transformer on the Range Relay Board. This transformer generates an
AC voltage that is proportional to the output current. The current transformer burden resistor
has two different values for the two current measurement ranges. The relay for the
measurement ranges is controlled by the AMP 4 line.
The Range Relay Board also has an instrumentation amplifier. This amplifier is used to
remotely sense the output voltage. The signal from the instrumentation amplifier is
SENSE A.
5.5 Amplifier Module
The AC Power Source uses a switch-mode full bridge amplifier module to obtain high
efficiency. The switched mode amplifier operates at 200 kHz. The amplifier module is
designated A7.
The Amplifier Module obtains its input signal from the Current Limit Board. A 5.0V RMS
input signal will generate a full-scale output voltage at the output of the AC Power Source
and 100.0V RMS on the primary of the output transformer.
The Amplifier Module requires 300 VDC,
±
15VSW and +15VSW1 supplies. The +300 VDC
supply comes from the DC input power supply.
The Amplifier Module has a thermo-switch mounted on its heat sink. If the heat sink
temperature exceeds 100 degrees C, the amplifier shuts down and sends an OVT signal to
the oscillator module. Logic low on the OVT control line will cause the front panel FAULT
indicator to be illuminated.
40 April 2007 2001RP