Wavetek 3000 - DPS2 A - Power Supply; +18 V Supply; -18 V Supply; +7.3 V Supply

THEORY
OF OPERATION
The two internal oscillators are ampli-
fied/leveled
by the same circuit
for
simplicity
but separately energized by
the FREQ switch .
The oscillators are
twin
T
oscillators, one is at 400 Hz the
other is at
1
kHz .
3.4.2 AccuracyLights
Which LEDs are lit is determinedby the
MODE switch . If any of the phase locked
loops unlock, the energized LEDs are
made to flashby an IC timer which is
activated by a DC level from any of the
four phase locked loops in the instru-
ment .
3 .5
DPS2A - POWERSUPPLY
The DPS2

provides DC power for
the rest
of the instrument . See Figure 3-10 .
3.5.1 Transformer & Filters
The transformersteps down the line vol-
tage to appropriate levels for the three
circuits . Full wave
rectifiers
and
filtercapacitors convert this voltage
to DC .
3-10
AC
L
lNE
3 .5 .2 +18V SUPPLY
The +18 V circuit has a
temperature-
compensatedprecision voltage
reference .
This reference iscompared to the output
voltage by an error amplifier
which
corrects any error in the
output voltage .
3
.5.3
-18 V SUPPLY
The -18 Vcircuitcompares the
+
.18 V and
-18 V outputs and holds the difference
in their magnitudes to zero .
3 .5 .4 +7 .3 V SUPPLY
The
+7
.3 V circuit uses . a three-terminal
adjustablevoltageregulator IC to pro-
videa pre-regulated
i-7 .3
V output .
This voltage supplies other voltage
regulatorsthroughout the
instrument .
Figure 3-10 .

DPS2 - Power
Supply .
4 /8 voc rs
-
lB
voc rs
-f- 7 .
3 vo
c
rs