Constant Current - Metek Sorensen XEL serie Manual De Operación

Constant Voltage
The output voltage is adjusted using the main and fine VOLTAGE controls; the CURRENT control
sets the maximum current that can be supplied.

Constant Current

If the load resistance is low enough such that, at the output voltage set, a current greater than the
current limit setting would flow, the power supply will automatically move into constant current
operation. The current output is adjusted by the CURRENT control and the VOLTAGE controls set
the maximum voltage that can be generated.
The CC indicator lights to show constant current mode.
Instantaneous Current Output
The current limit control can be set to limit the continuous output current to levels down to 0.1mA
(0.01mA on 75mA range). However, in common with all precision bench power supplies, a capacitor
is connected across the output to maintain stability and good transient response. This capacitor
charges to the output voltage and loading of the output will produce a current pulse as the capacitor
discharges which is independent of the current limit setting.
Current Meter Averaging
Connection to the Load
The load should be connected to the positive (red) and negative (black) OUTPUT terminals. Both
are fully floating and either can be connected to ground.
Warning! Voltages above 70Vdc are hazardous live according to EN 61010-1 and great
care must be taken when using the power supply at voltages above this level.
It is highly recommended that connections are only made using leads fitted with
fixed-shroud 4mm safety plugs. Make sure that the circuit to which connections
are made is appropriately insulated; no accessible parts of the external circuit
should become hazardous live in normal or single fault condition as defined by
EN61010-1.
Always make connections to the instrument with the OUTPUT off.
Remote Sensing
The use of remote sense is seldom required because the maximum output current of the instrument
is low. However, even at low currents the resistance of connecting leads can result in differences
between the indicated source voltage and the actual load voltage (two 200mΩ connecting leads will
drop 0.2V at 500 mA, for instance).
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To reduce the measurement jitter with rapidly varying load
currents a 2-second time constant can be selected by pressing the
METER AVERAGE key; the indicator beside the key lights when
meter averaging is selected. Press the key again to CANCEL
meter averaging and return to the standard 20ms time constant.
This problem can be minimized by using short, thick, connecting
leads, but where necessary it can be completely overcome by
using the remote sense facility.
This requires the sense terminals to be connected to the output
at the load instead of at the source; insert wires into the spring-
loaded SENSE terminals and connect directly to the load. Switch
the LOCAL/REMOTE switch to REMOTE.