Atek 10002iX, User Manual

Page: 129 / 259

User Manual California Instruments
5.Principle of Operation
5.1General
An explanation of the circuits in the NSG 1007-3 and NSG 1007-5-208 is given in this section.
Refer to Figure 5-72 for a block diagram of the system. Figure 5-2 shows the system
interconnect schematic.
OUTPUT AC
CHOKE POWER
BOARD AC
BULK I/O
CAPS. LOGIC
BOARD DC
POWER BOARD
BRIDGE BOARD
RECT
CUR LIMIT BOARD
3 PHASE INPUT
OSC ASSY.
Figure 5-72: AC Power System Block Diagram
5.2Overall 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.
NSG 1007 Series II 129