CURRENT CHANNEL
Output current is controlled continuously throughout the specified adjustment range via a 10-turn potentiometer mounted behind the front panel. External control can be exercised by control voltage.Current Limit Programming. HSP power supplies provide two different methods for programming the output current limit point: internal and external voltage. When using internal programming, the minimum programmable current limit is 50-60% of nominal, while external voltage programming permits adjustment down to near zero. The programming method is selected via S3 switch positions 2 and 3 as follows:
| Internal Programming: | This is the factory-set (default) mode; when enabled via S3-3, the current limit is adjusted via the front panel potentiometer labeled IMAX. |
| External Voltage Programming: | When enabled via S3-2, this mode provides for current limit adjustment via an
external voltage source (0-10V) connected between pins 15 and 19 (IPROG, -S)
of the I/O connector. This technique is useful when implementing
digital control of the power supply current limit via a D/A converter; Kepco's
SN/SNR 488 programmers are ideally suited to these requirements.
|
Current Limit Programming Range: The user may select the maximum programmable current limit, either high or low range, via S3 switch position 1. This permits the user to trade adjustment range for programming resolution; this is especially useful when used in conjunction with external voltage programming for precise limit adjustment, or for limiting the maximum programmable current limit. Operation of the range selector is as follows:
- High Range:
This is the factory-set (default) mode; the maximum programmable current
limit is 110% of rated IO for all models.
- Low Range:
When enabled via S3-1, the maximum programmable current limit is equal to the
rated output current IO for all models; since the programming voltage range
does not change, the resolution for a given programming input increment increases by 10%.
