Mother Board; Amplifier Modules; Oscillator Module; Range/Relay Board - Ametek 2003RP User And Programming Manual

5.4 Mother Board

The Mother board, module assembly A5, routes signals between the various assemblies in
the power source.
The Mother board also has circuits that scale the oscillator reference waveforms for the two
different voltage ranges.
The oscillator reference waveforms are also adjusted via potentiometers:
1. Phase A, adjust via R4, monitor at TP4
2. Phase B, adjust via R8, monitor at TP5
3. Phase C, adjust via R12, monitor at TP6

5.5 Amplifier Modules

The AC Power Source has three switched mode amplifier modules to obtain high efficiency
AC outputs. The switched mode amplifiers operate at 200 kHz. These amplifier modules
are designated A7, A8, and A9.
Each Amplifier Module obtains its input signal from the Oscillator Assembly via the Mother
Board. A 5.0V RMS input signal will generate 100.0V RMS on the primaries of the output
transformers and full-scale output voltage at the outputs of the AC Power Source.
Each Amplifier Module requires a 300 VDC, 15VSW and +15VSW1 supplies. The +300
VDC supply comes from the DC supply through one 20 amp fuse on the DC Supply and one
of three 5 amp fuses on the Mother Board.
Each Amplifier Module has a thermal 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 any of the OVT control lines will cause the front panel
FAULT indicator to be illuminated.

5.6 Oscillator Module

The Oscillator Assembly consists of two boards, the Controller board, A1, and the Phase B/C
board, A2. The Phase B/C board connects to the Controller board via a ribbon cable. The
controller board connects to the mother board via another ribbon cable.
The Oscillator assembly has the circuits to perform the following operations:
1. Generates the output voltage sinewave for phase A, B and C.
2. Interprets the Voltage, Frequency and Current limit commands from the front panel and
RS232/GRIB Board.
3. Attenuates the oscillator drive signals to operate in a constant current mode.
4. Measures the output voltage, current, peak current and power for the selected output
phase.
5. Performs voltage dropouts at a designated phase angle or one or more output phases.

5.7 Range/Relay Board

The Range/Relay board, module assembly A6, holds the AC Power Source voltage range
change relays. These relays are controlled by the LVR line.