Keithley Series 2200, User Manual

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Operating Basics
Con fi gure The Instrument for Your Application
The menu system includes settings, like Max Volt , that determine the maximum voltage output of the power supply and
settings, like Save Last and Output Recall , that determine how the instrument initializes itself at power-up.
This power supply features a constant voltage/constant current automatic crossover. This feature permits continuous
operation in the transition from constant-voltage mode to constant-current mode as the load changes. The intersection of
the constant-current and constant-voltage modes is called the crossover point.
For example, if the load is such that the power supply is operating in constant-voltage mode, the power supply provides
a regulated output voltage. As the load draws more current, the output voltage remains constant until the preset current
limit is reached. Then the crossover occurs. At that point, the output current becomes constant and the output voltage
drops in proportion to further load increases.
Crossover is indicated by the front-panel CC and CV messages. If the CV message appears, the instrument is operating in
constant-voltage mode. If the CC message appears, the instrument is operating in constant-current mode.
Crossover from the constant-current mode to the constant-voltage mode also occurs automatically in response to a
decrease in load current.
Connect to a Device Under Test
You can connect this instrument to a device that you want to test. In this section are procedures for con fi gurations using local
and remote sense, and examples for parallel, serial, and bipolar wiring connections.
NOTE. When connecting to a device under test, you should use at least a 22 gauge wire, which is the minimum wire
size suf fi cient to handle the maximum current.
WARNING.
Use properly rated load wires. All load wires must be heavy enough not to overheat when carrying the maximum
short-circuit output current of the power supply. If there is more than one load, then any pair of load wires must be capable
of safely carrying the full-rated short-circuit output current of the power supply.
WARNING. To satisfy safety requirements, always use load wires heavy enough not to overheat when carrying the maximum
short-circuit output current of the power supply. If there is more than one load, then every pair of load wires must be capable
of safely carrying the full-rated current of the power supply.
Set Up to Use Local Sense
Con fi guring the power supply for local sense allows connection to the device under test with two lead wires, but does
not compensate for voltage drop in the leads.
1. On the rear-panel terminal strip, install wires or the supplied shorting clips between drive OUT + and SENSE +, and
between drive OUT - and SENSE -. When using the included shorting clips, they should be installed as shown
previously.(See page 9,
Rear-panel Features .)
2. Connect to your device under test using two wires from the front-panel binding posts.
22 Series 2200 Multi-Channel Programmable DC Power Supplies User Manual