Wavetek 132 Manual page 14

GENERAL DESCRIPTION
Refer to the block diagram of the Model 132 VCG/
Noise Generator, Figure 3-l.
Basically, a square wave is applied to the input of an
integrator composed of a wide-band differential dc
amplifier, integrating resistor and capacitor. Output
VCG
VCG
Cl RCUIT
POWER
SUPPLIES
DIGITAL
I
FILTER
I
I
I
I
H Y S T E R E S I S
OUTPUT
SWITCH
+5 v
+15 v
-15 v
CONVERTER
23
Figure 3-l. Functional Block Diagram
CIRCUIT DESCRIPTION
of the integrator is fed into the hysteresis switch.
The hysteresis and output switches function like a
Schmitt trigger with the limit points set at the wave-
form extremes, firing when the triangle wave reaches
+1.25 volts and -1.25 volts. When firing occurs, the
hysteresis and output switches are set, reversing the
square wave fed into the integrator. Reversal of the
square wave causes the triangle wave to reverse direc-
SINE
SECTION 3
ATTENUATOR
I
MODE
S W I T C H I N G
C I R C U I T
FUNC
SYNC
OUT
NOISE
SYNC
NOISE
CLOCK
11