AMETEK i-iX Series II - Manual (Page 129)

User Manual California Instruments
i Series II / iX Series II / iM Series II 129
5.2 Overall Description
Three or single phase input power is routed in from the back panel through an EMI filter and the
circuit breaker to the input bridge rectifier. The DC output from the bridge rectifier is smoothed
by a small amount of capacitance in order to keep the input power factor as high as possible.
This DC output supplies the converter on the DC power board.
The DC converter turns the unregulated rectified AC into a smoothed, isolated, tightly regulated
DC supply. Also mounted on the DC power board is the auxiliary power supply. The auxiliary
power supply creates low voltages to operate the control logic board, the oscillator board, the AC
power board, and the fan. The output of the DC converter is fed to two large electrolytic
capacitors on the I/O board. These capacitors also provide holdover storage energy to ride
through line dropouts.
The AC power board takes the DC input and puts out isolated, direct coupled, AC power.
The DC bus is regulated at 250 volts for the 135/150 VAC output and 500 volts for the 270/300
VAC output.
The oscillator assembly generates the reference waveforms and provides frequency, amplitude,
and impedance control. The current limit board, in conjunction with the oscillator board, provides
the current limit function.
The assemblies are described in more detail in the following paragraphs. Refer to Figure 5-1 for
an overall block diagram.
5.3 Oscillator Assembly
The oscillator assembly consists of three printed circuit board assemblies connected by a ribbon
cable. The oscillator generates the sine wave signal setting the frequency, amplitude and
current limit level. It also senses the output voltage to provide closed loop control of the output.
5.3.1 CPU Board
This board assembly, A7, consists of the components for the CPU (DSP), generating the Phase
waveform signals to the power amplifiers, programmable impedance (iX models only) and all of
the program, waveform and data memory. In addition, the waveform board contains the circuits
for all measurements. The clock and lock circuit required to support the clock and lock mode of
operation of multiple i/iX units is also on this board assembly. For three phase i/iX models, all
three phases are contained on the same board assembly 7003-718-3 (1 phase) or 7003-718-1
(3 phase). If the -413 option is present, a separate inter harmonic generator board is connected
to the CPU board.
5.3.2 Keyboard/Display Board
The keyboard/display assembly is assembly A9. It is mounted to the front panel and holds the
23 rubber keys. It also has the LCD graphics display. A shaft encoder is mounted on the board
that is used for a shuttle input.
5.3.3 GPIB / RS232 or GPIB / RS232 / USB / LAN IO Board
This board assembly is identified as A10. It has the IEEE 488, RS232 and USB transceivers and
optionally an Ethernet interface (-LAN option). USB and LAN are available on top assembly
7000-485 and 7000-486 iX/i models only. It also has isolators to provide safety isolation for all
control interfaces.