GW Instek APS-9000 Series - Manual (Page 8)

APS-9301 & APS-9501 & APS-9102 User’s Manual
14
6. Circuit Principle
The APS series products are controlled by CPU and operated via keyboard.
The APS series are fully digital controlled.
The input isolate transformer has bee applied to isolate the city power from
the APS series. And step down the input voltage for appropriate applications.
The main AC power is rectified and filtered to become a very smooth DC
source for power amplifier. Sine ware form is generated by the digital
synthesizer and filtered by a very high impedance filter. Therefore, the sine
ware form will be very stable and the distortion will be reduced.
The APS series have two voltage feedback systems. One is analog feedback
system for quick response(within 100us), and the regulation will be located In
the range of ±5%. The other is digital feedback system. The system will read
the output voltage and compare with the settings. The accuracy of Output
voltage will be limited in the range of ±0.1V.
The sine wave signal is amplified by power amplifier. The power amplifier
provides a very clean and low distortion sine ware to the output of APS series
through the output transformer. The offset and calibration data of
instrumentation are stored in the EEPROM. The instrumentation would be
Calibrated automatically when the APS series is switched on. True RMS
circuit is applied for the voltmeter and ammeter. The value of LED display
is true RMS value.
For easy operation, the APS series equips a memory of EEPROM. The
EEPROM will memorize the latest settings data automatically after the APS
Series have been switched off. If the APS series is switched on again, the
CPU could read all the data from the EEPROM and provide the output value
same as the previous setting. It is unnecessary to reset the data after APS
series are switched off.
APS-9301 & APS-9501 & APS-9102 User’s Manual
15
7. Block Diagram
I/P
C
P
U
Keyboard
Display
Voltage
Control
Frequency
Control
Frequency
Sensor
Memory
A/D
Isolated
Transformer
Rect. /
Filter
Power
Amplifier
Sine wave
Synthesizer
Output
Transformer
Current &
Voltage
Feedback
Current &
Voltage
Sensor
O/P