Tektronix FG 5010 User Manual

Theory
of
Operation
-
FG 5010
Phase - Lock Delay Mode . In this mode , the Frequency
Control circuits are used to delay the signal from the Lock
Detctor to the
CPU until the
phase - lock circuits
have had
time
to settle
down . The CPU
start signal
at
U1212B pin 3 is
held
low
during
this
operation to
disable
the
Reference
Counter . Thus , U1210A is enabled to pass the phase - lock
control
via
pin 1 of the
gate .
When the Lock Detector output at pin 9 of U1210C goes
high
, the
output of
U1210C , pin 8 ,
also
moves high . The
positive transition from U1210C is passed through U1212C
and
U1210A , inverted
by the
former , and sets
U1220A
. Just
previously ,
the CPU has
loaded
latches
U1122 and
U1112
with
the
appropriate
number , and
the high
at pin 8 of
U1222C reset the flip - flop and the counters were loaded .
Thus , U1230A pin 6 is low , so U1222A cannot reset
U1220A . Since U1220A is set , the next negative edge from
INTRODUCTION
The Sine Shaper Section consists of the following major
circuits , which are depicted on Diagrams 20 through 23 :
Latches , the N Burst Circuits , the Sine Shaping Circuit , the
Sine Buffer , the Trigger Interfaces , the Square - wave Buffer ,
and the
and
-12 V
Regulators
.
The
following
block
diagram
description includes
all of
the elements depicted on the Sine Shaper Block Diagram .
However , since not all of the circuits so depicted are
considered to be part of the main flow of signal events ,
those circuits are discussed later in this description . Those
include the Latch Circuits and N Burst Circuits ( Diagram 20 ) ,
and the + and -12 V Regulator Circuits ( Diagram 23 ) .
4-28
SINE SHAPER SECTION
BLOCK DIAGRAM DESCRIPTION
As noted by the title , one of the major functions of the
Sine Shaper is to form a sinusoidal signal from
triangle
wave signal . The HF or LF triangle - wave signal from the
Loop 1 circuits is applied to the Sine Shaping Diodes for
conversion to sine waves , or applied directly to the Output
Amplifier
circuits ,
depending on the
function that
is selected
.
If sine wave is selected , the triangle - wave signal is applied
to
the Sine
Shaping Diodes
, and the
resulting
sinusoidal
signal is applied to the Sine Buffer . The Sine Buffer applies
the sine - wave output signal to the Output Amplifier , if sine
wave operation has been selected , or into
a
75Ω
termination if not .
U1222B will set U1220B . This enables the Loop Cycle
Counter to
decrement to zero
. When zero
occurs ,
U1230A
enables
U1220B to reset
, and
through
U1222A
resets
U1220A .
At the next
negative
edge to pin 5 ,
U1220B
resets ,
stopping
the
counters
.
The low at
pin
9
of
U1220B
loads
the
next
number from
the latches
. The high
from pin
8 of the
flip
flop
informs the
CPU via
U1430 pin
15 that
the
settle -
down
time
is over
, and the
Lock
Detector
output
applied at
U1430
pin
14 can
now be
examined .
If the Phase - Lock circuit loses lock on the signal com
pletely , or the
CPU
moves to
terminate the
operation
,
either
pin
9 or
10 of
U1210C ,
respectively
, will
move
low . This
change
is
coupled
through and
inverted to
U1222C
pin 8
,
which will reset U1220B and terminate the operation
immediately .
The
square
-
wave
signals from Loop
1 are
applied to the
Square -
wave Buffer
and the
Trigger
Interfaces ,
which pro
vide the TRIG OUT and TRIG COMPL OUT signals . Nor
mally , TRIG OUT is connected to the front - panel TRIG
OUTPUT connector , although TRIG COMPL OUT may be
connected instead . The Trigger Interface also applies a
square
- wave
signal to
the N
Burst
Counter
,
which
counts
the
programmed
number of
cycles
before sending the END
OF BURST signal to the Loop 1 Logic circuits .
Also on this board are the + and -12 V regulators ,
which use the output of the + and -26 V regulators in the
Power Module to generate the two voltages .
SINE
SHAPER
AND
BUFFER
Introduction
The Sine Shaper and Buffer circuits shape the applied
triangle into a low - distortion sine wave , which is amplified
for transmission to the Function Selector , and eventually to
the
Output
Amplifier
.
Sine
Shaper
The Sine Shaping Diodes consist of the input circuit and
four
diode - bridge
networks . Each
of the diode
- bridge net
works
consists of a pair
of precision
resistors , one
of which
returns to +12 V , the other of which returns to - 12 V ; and
four matched Schottky barrier diodes .
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Tektronix FG 5010 Specifications

General

Brand	Tektronix
Model	FG 5010
Category	Portable Generator
Language	English