Keithley 2790 User Manual

1-2 Model 2790 SourceMeter
®
Switch System User’s Manual
Introduction
When used with one or two switching modules, the Model 2790 can be used to test inflators.
With a 7751/7752/7753 module, the Model 2790 can safely measure the resistance of
bridgewires and shunt bars. With a Model 7751 or 7753 module, the Model 2790 can use the
high voltage method to measure the insulation resistance of an inflator. The 7702 module can
be used for ohms testing that requires 20/40 channels of 4-wire/2-wire measurements.
Key features
• Programmable I-source — The 7751, 7752, and 7753 modules have a built-in
programmable current source (0 to 50mA). This constant current source is used to
measure the resistance of bridgewires and shunt bars.
The Model 2790 has a low-ohms math function: SxIohms. It calculates (using the
programmed current and measured voltage) and displays the resistance (in ohms)
of the bridgewire or shunt bar. X is the slot number of the module being used.
• Programmable V-source — The 7751 and 7753 modules have a built-in program-
mable voltage source (50 to 500V) and an I/V converter to measure the insulation
resistance of an inflator. Current through the insulator is applied to the I/V con-
verter where it is converted to a voltage that is measured by the Model 2790.
The Model 2790 has a high-ohms math function: SxVohms. It calculates (using the
programmed V-source voltage and measured I/V converter output voltage) and dis-
plays the resistance (in ohms) of the insulation. X is the slot number of the module
being used.
• Safety features — The Model 2790 has built-in safety features to reduce the possi-
bility of inflator ignition and damage to the module due to excessive current.
• Interlock — The interlock feature of a 7751/7752/7753 module disconnects
the sources (I-source and V-source) from the switching matrix. Details on the
interlock are provided in Section 5.
• Fuses — Current limiting fuses for the current source of the Model 2790
DMM and the I-source of the 7751/7752/7753 module.
• I-source current limiting — An active, high-speed current limiting circuitry
for the I-source of the 7751, 7752, and 7753 modules.
• V-source current limiting — An impedance circuit limits current to <1mA.

Keithley 2790 Specifications

General

Brand	Keithley
Model	2790
Category	Switch
Language	English