Keithley 2657A User Manual

Section 4: Theory of operation Model 2657A High Power System SourceMeter® Instrument Reference Manual
4-22 2657A-901-01 Rev. B/December 2012
Figure 88: Contact check circuit configuration
Remote
SENSE HI
HI
Remote
LO
SENSE LO
Local
Local
x1
GUARD
CCHK SW
CCHK SW
+
–
1
2
2
4
4
1
2
3
3
Aggregate
contact
resistances
Feedback
V-source
+
-
50 μA
current source
I-meter
A
V
V-meter
50 μA
current source
NOTES: 1. This represents a protection circuit. Do not apply more than 3030 V
between HI and SENSE HI. To maintain specified operation and obtain
accurate measurements, the maximum voltage between HI and
SENSE HI should be no more than 3 V. This limit also applies to
the maximum voltage between LO and SENSE LO.
2. Approximately 80 kΩ.
3. High impedance differential amplifier.
4. Approximately 10 MΩ.

Keithley 2657A Specifications

General

Brand	Keithley
Model	2657A
Category	Measuring Instruments
Language	English