Table of Contents
Advertisement
b.
Connect a capacitor having similar char¬
acteristics (approximately same capacitance, same
voltage rating or greater, and having good high fre¬
quency characteristics) across the load using short
leads.
3-31 Although the strapping patterns shown in
Figures 3-3 through 3-5 employ local sensing, note
that it is possible to operate a power supply simul¬
taneously in the remote sensing and Constant Volt¬
age/Current Limit remote programming modes.
NOTE
It is necessary to readjust the current
limit when the instrument is operated
in the remote sensing mode.
3-32
SERIES OPERATION
3-33
Normal Series Connections (Figure 3-7).
Two
or more power supplies can be operated in series to
obtain a higher voltage than that available from a
single supply.
When this connection is used, the
output voltage is the sum of the voltages of the in¬
dividual supplies.
Each of the individual supplies
must be adjusted in order to obtain the total output
voltage.
The power supply contains a protective
diode connected internally across the output which
protects the supply if one power supply is turned off
while its series partner(s) is on.
Rx
Figure 3-7.
Top:
Normal Series; Bottom:
Auto-Series, Two Units
3^34 Auto-Series Connections (Figure 3-8).
The
Auto-Series comfiguration is used when it is desii
able to have the output voltage of each of the
series connected supplies vary in accordance witl
the setting of a control unit.
The control unit is
called the master; the controlled units are called
slaves.
At maximum output voltage, the voltage
of the slaves is determined by the setting of the
front panel VOLTAGE control on the master.
The
master supply must be the most positive supply of
the series.
The output CURRENT controls of all
series units are operative and the current limit is
equal to the lowest control setting.
If any output
CURRENT controls are set too low, automatic
crossover to constant current operation will occur
and the output voltage will drop.
Remote sensing
and programming can be used; however, the strap¬
ping arrangements shown in the applicable figures
show local, sensing and programming.
Figure 3-8,
Auto-Series, Three Units
3-35 In order to maintain the temperature coeffi¬
cient and stability specifications of the power sup¬
ply, the external resistors (Rx) shown in Figure 3-8
should be stable, low noise, low temperature coef¬
ficient. (less than 5 ppm per degree Centigrade)
resistors.
The value of each resistor is dependant
on the desired output voltage ratings of the master
and slave supplies.
The value of Rx is this voltage
divided by the voltage programming current of the
supply, lma (1/Kp where Kp is the voltage program¬
ming coefficient).
Advertisement
Table of Contents
Troubleshooting
