11
(CR), constant power (CP) and eight basic operating modes: CCL, CCH, CV, CRL, CRM, CRH, CPV and
CPC.
The operating mode and
the associated
parameters can be set via front panel or remote command.
The load will
remain in current mode
until the mode is changed
. If the mode is changed when the
load’s input is in ON status, the load will be turned off for around 5ms automatically.
The set value for electronic load becomes effective immediately when the load is turned on. If the
input set value exceeds the allowed range, it will be automatically limited at maximum value or
minimum value.
2.3.1 Constant Current Mode
Constant current mode has two ranges, the high range (CCH) and the low range (CCL). The high
range provides wider test range.
The low range provides better resolution at low current settings
. In
CC mode,
the
load
will sink a constant current in accordance with the programmed value
regardless of the change of input voltage
(see Fig.2-1). Press
key in basic mode to enter into
mode selection and parameter setting menu. Choose CCH or CCL mode with
and
keys.
Input the current level via the Entry keys or the knob with
and
keys. Use
key for
confirmation. The CC mode and parameters can also be set via remote command (MODE CCL,
MODE CCH, CURRent <NRf+>).
Fig.2-1 CC Mode
2.3.1.1 Setting Ranges
The setting ranges for different models of load are listed as follows:
Model 3720A 3721A 3722A 3723A 3724A
Mode
CCL 0~3A 0~40A 0~2A 0~3A 0~2A
CCH 0~30A 0~40A 0~20A 0~30A 0~20A
If the range is changed in CC mode while the load’s input stays in ON status, the load will be
turned off for around 5ms automatically. For example: when the load is switched from CCL to CCH,
the input will be turned off around 5ms. Besides, it is noted that the current set level may change with
the current level to fit the new range. Take 3721A as an example, the present setting is CCH 10.000A,
when the load is switched from CCH to CCL, the current set level will change to the maximum level
4.0000A for CCL.
