Specifications
5.10
POWER
SUPPLY -
H7865
5.10.1
OPERATION
The
H7865
power
suppl~
is
a
sinsle
endedfswitch
t~pe,
re~ulated
AC-DC
converter
circuit.
It
utilizes
a
uni-directional
transformer
in
a
half
wave
transformer
coupled
mode.
The
unit
operates
at
a
constant
freQuenc~
and
re~ulation
is
achieved
b~
pulse
width
modulation
of
the
inverter
primar~
current
conduction
time.
Primar~
ener~~
storase
is
in
the
input
filter
capacitors
at
approximatel~
300V
DC.
Discrete
pulses
of
known
current
are
provided
to
the
UDT
primar~
windins
with
each
tris~ered
period
of
operation.
This
current
is
transformed
b~
the
UDT
and
is
available
at
lower
voltase
and
hi~her
current
at
the
secondar~
windinSs
of
the
UDT.
B~
increasinS
or
decreasin~
the
pulse
width,
the
available
output
voltase
is
affect~d
correspondinSl~.
Hence,
a
constant
output
DC
yoltase
is
maintained
with
var~in~
lines
and
loads
b~
increasins
or
decreasins
the
converter
pulse
width.
5.10.2
ELECTRICAL
SPECIFICATIONS
5.10.2.1
AC
INPUT
SPECIFICATIONS
5.10.2.2
LINE
VOLTAGE
Line
voltase
input
ran~e
is
selected
b~
an
operator
accessible
switch
located
near
the
AC
inlet
connector.
This
switch
reQuires
a
small
tool,
such
as
a
screwdriver
to
operate.
120V
AC
nominal,
single
phase,
3
wire.
87V
AC
to
128V AC.
220V
AC
nominal,
sinsle
phase,
3
wire.
174V
AC
to
256V
AC.
5.10.3
FREGUENCY
5.10.4
CURRENT
5.10.4.1
6A
RMS
Maximum
(87V
AC
input
for
full
rated
5.10.4.2
output)
4A
RMS
Maximum
(174V
AC
input
for
full
rated
output)
5.10.5
POWER
FACTOR
The
power
factor
____
RMS
WATTS_______
of
the
input
shall
be
~reater
RMS
volts
x
RMS
amps
than
0.60
at
full
output
power
and
120V
AC,
60
Hz
line.