HP (Hewlett-Packard) 6205B ユーザーズマニュアル

Figure 3-4.

Remote Resistance Programming

3-21 To maintain the stability and temperature

coefficient of the power supply, u se programming
resistors that have stable, low noise, and low
temperature (less than 30ppm per degree Centi-

grade) characteristics.

A switch can be used in

conjunction with various resistance values in
order to obtain discrete output voltages.

The

switch should have make-before-break contacts

to avoid momentarily opening the programming
terminals during the switching interval.

3-22 Voltage Programming (Figure 3-5). Employ

the strapping pattern shown on Figure 3-5 for
voltage programming.

In this mode, the output

voltage will vary in a 1 to 1 ratio with the pro-

gramming voltage (reference voltage) and the load

on the programming voltage source will not exceed
25 microampere.

Figure 3-5.

Remote Voltage Programming

3-23 The impedance (Rx) looking into the external

programming voltage source should be approxi-
mately  1000 ohms if the temperature and stability

specifications of the power supply are to be main-
tained.

The programming accuracy is 1% of the

programmed voltage.

3-24 Methods of voltage programming with gain

are discussed in Application Note 90, Power Supply

Handbook; available at no charge from your local

Sales Office.

3-26 Remote sensing is used to maintain good

regulation at the load and reduce the degradation
of regulation which would occur due to the voltage
drop in the leads between the power supply and
the load.

Remote sensing is accomplished by uti-

The power supply should be turned off before
changing strapping patterns. The leads from the

+S terminals to the load will carry less than 10
milliamperes of current, and it is not required that
these leads be as heavy as the load leads.  H o w -

ever, they  must be twisted or shielded to minimize

noise pick-up.

Observe polarity when connecting the
sensing leads to the load.

Figure 3-6.

Remote Sensing

3-27 For reasonable load lead lengths, remote

sensing greatly improves the performance of the
supply. However, if the load is located a consid-

erable distance from the supply, added precautions
must be observed to obtain satisfactory operation.

Notice that the voltage drop in the load leads sub-

3-3