Cisco 2811 - Voice Security Bundle Router Quick Start Manual page 25

Note When source A and source B are wired with common negative terminals, as in Figure 22, discharging does not occur
and there is no restriction requiring that source A and source B voltages be equal.
Figure 23 Connecting Source A and Source B with Common Positive Terminals
Va voltage = Vb voltage (within 0.25 V)
Va
+
+
Vb
In Figure 24, source A and source B are wired with opposite polarity grounds. Do not use this configuration.
Do not use the DC input configuration shown in Figure 24.
Caution
Figure 24 Source A and Source B Wired with Opposite-Polarity Grounds
Va Va
+ +
+ +
Vb Vb
Va voltage = Vb voltage (greater than 0.25 V)
A-
A+
B+
B-
A- A-
A+ A+
B+ B+
B- B-
A- A-
Va Va
+ +
A+ A+
B+ B+
+ +
Vb Vb
B- B-
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