Wayne Kerr AP10030, Руководство пользователя и обслуживания

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Wayne Kerr AP 1kW Power Supplies • Issue 2 23
6.4.3 Remote Programming
This section deals with the remote programming of the power supply output via the rear
barrier strip terminals. The terminals are accessible when the terminal cover is removed.
Units fitted with the IEEE488 option (which allows remote programming via the IEEE
bus) may also be controlled in this way when set for local operation. Programming with
the IEEE interface is dealt with in a separate manual.
The connections available on the rear terminal strip allow the power supply voltage and
current values to be remotely programmed using either voltage, resistive or current
programming. The power supply is essentially voltage programmable but two constant
current sources are provided which, for normal operation, are used in conjunction with
the front panel controls to give, what is in effect, resistive programming. Current sources,
front panel controls and the voltage programming inputs can be connected to external
resistors, voltage sources and current sources to give various programming options.
Examples of the more common options are given.
a) Remote Resistive Programming
Controlling The Output Voltage
6
6
7
7
8
8
9 10
Vprog Common
-S -S
Programming resistor
0-4k7 for 0 to full scale O/P
Optional resistor for
lower voltage limit
Optional resistor for
upper voltage limit
6 - Voltage programme input
7 - Front panel control
8 - Constant current source
Fig. 6.4. Connections for resistive programming output voltage
Connections as shown in Fig. 6.4 will give remote resistive programming of the output
voltage. A resistor variable from 0 to 4.7k Ω will produce an output voltage of zero to full
scale. Upper and lower limits can be set by connecting fixed resistors in parallel or series
with the remote variable resistor. A fixed resistor in series will set a lower limit and one
in parallel an upper limit. Upper and lower limits for the front panel potentiometers can
also be set if required. The front panel potentiometer is connected as a variable resistor
from terminal 7 to negative sense. Fixed resistors can be wired in series or parallel with
the front panel potentiometer to limit the output as previously described. The front panel
potentiometer is of nominal 5k
Ω value
±
5%.
N.B. If a resistor is added in series with the front panel potentiometer the maximum total
resistance would be greater than 5k
Ω . This would not damage the unit but some of the
travel of the front panel control would be lost. An upper limiting resistor should be
connected in parallel with the resistor combination.