Chapter 3
Theory of Operation
Introduction
Refer to Figure
3.1
while reading the following.
The
power supply provides regulated voltages used by the various compo-
nents within the Z-100
PC
Series Computers. The power supply
is
located
toward the rear and to the right of the chassis, and uses a quasi square
wave switching regulator to produce three regulated output voltages. This
unit complies with FCC, VDE, CSA, and UL regulations.
Outputs
All
outputs from the precision-regulated power supply are electrically iso-
lated from the main voltage and share a common ground, which is the
chassis of the power supply.
The
voltages output to disk drive connectors
P1
and
P2
have special
requirements for output ripple frequency components
in
the frequency
range
of 60 to 120 KHz. To obtain these low levels, a low pass filter
is
added to the regular output leads of
P1
and
P2.
The output ripple
is
measured with an oscilloscope with a bandwidth of 3 KHz. Component
frequency of the output ripple of the 5-volt or 12-volt outputs should NOT
exceed 2 mV peak between the frequencies of 60 KHz to 120 KHz. Con-
nector P3 supplies the output voltages to the backplane board.
