User Connections 65
Connecting Supplies in Series
Floating voltages must not exceed ±240 Vdc. No output terminal may be more than 240 V from
chassis ground.
Figure 4-3f shows how power supplies can be connected in series for higher voltage output.
Series connections are straightforward in this case. Program each power supply independently. If two supplies are used in
the series configuration, program each supply for 50% of the total output voltage. Set the current limit of each supply to the
maximum that the load can handle without damage.
Each power supply has a reverse voltage protection diode across its output. If a reverse voltage is
applied, the supply cannot control the current conducted through this diode. To avoid damaging the
supply, never connect it in such a way that a reverse voltage can force it to conduct current in
excess of the supply’s maximum reverse diode current (see Table 1-2).
Analog Connector óLoad Connection ìLoad
A Program each supply for full load current and 1/2 the load voltage
B Set switch for local or (optional) remote sensing
C Connect for remote sensing (optional)
WARNING
FLOATING VOLTAGES MUST NOT EXCEED ±240 VDC. NO OUTPUT TERMINAL MAY
BE MORE THAN 240 V FROM CHASSIS GROUND
Figure 4-3f. Series 664xA and 665xA Series Connection (Remote Sensing Optional)
External Voltage Control
The setup shown in Figure 4-3g allows an external dc voltage to program the power supply output. A voltage applied to the
voltage programming input programs the output voltage and a voltage applied to the current programming input programs
the output current. See Figure 4-1 for an explanation of these programming input connections.
Wiring Considerations
The input impedance of the analog input is 10 kΩ. If the output impedance of your programming source is not negligible
with this, programming errors will result. Larger output impedances result in proportionally greater errors.