Keithley 7711, Руководство пользователя

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18
Application example
The following application example is for power supply testing. For basic overview and switching, refer to Figure 8 . For the
tests performed, refer to the provided code ( Figure 9 ). Basic knowledge for Visual Basic functions, such as the CStr() function,
as well as how forms work in Visual Basic, is required to fully understand the example.
Figure 8
Simplified connection schematic (one power supply shown)
Figure 9
Visual basic application example—power supply testing
'' ---------------------------------------------------------------------------------------------------------------------
'' 7711 Application Example
'' ---------------------------------------------------------------------------------------------------------------------
'' This program tests a set of power supplies using a 2750 loaded with a 7700,
'' 7711, and a 7705.
''
'' The following occurs:
'' 1) The 7700 takes DCV, ACV, 2W OHMS (CONT), and TEMP measurements.
'' 2) Limits are used in each of the measurements by the 7700.
'' A) DCV limits are set to 10% of the power supply's output.
'' B) ACV limits are 108 and 132V.
'' C) 2W OHMS limits are -0.01 and 2 ohms.
'' D) TEMP limits are 70 and 125 C.
''
'' 3) RF switching to an oscilloscope is obtained using a 7711 where the AC ripple
'' is measured.
''
'' 4) A 7705 is used to switch loads and to control the line input voltage
'' to the DUTs (power supplies).
''
'' Please note:
'' The maximum number of power supplies that can be used with this example is 4.
'' ---------------------------------------------------------------------------------------------------------------------
Oscilloscope
7712-SMA-1
Cable
Ch1
OUT A
Power Supply
Input Output
High Line
132V
Low Line
108V
~ ~
7705
Ch21
7705
Ch31
10%
Load
HI
LO
Ch1
Ch2
Ch3
Ch4
DCV
ACV
CONT
TEMP
HI
LO
HI
LO
7705
Ch1
7705
Ch11
Thermocouple
HI
LO
HI
LO
90%
Load
7711-SMA-BNC
Cable
7700
7711