Principles of Operation
LV 3620
4–5
Illustration 4–3 Sections of a variable impedance power supply
–
–
+
+
+Vcc
–Vcc
Parallel
Series
Parallel
V2
V1
+Vcc
–Vcc
Power
Supply
Input Signal
Load
Power
Supply
Voltage
Output
Voltage
The power transistors stay cooler and are not forced to needlessly dissipate heat. This is
the normal operating mode of the supply.
When the voltage requirements are high, the supplies switch to a
series mode
which
produces higher voltage and less current.
Sensing circuitry monitors the voltage of the signal to determine when to
switch
Bi-level
modes. The switching circuitry is designed to prevent
switching distortion to yield the highest possible dynamic transfer function.
This provides the maximum power with the maximum safety, and the best
power matching to a Bi-Level load.
Illustration 4–2 Output transistor power dissipation
