Introduction; Block Diagram Description - Tektronix 7B51 Instruction Manual

Circuit Description-Type 7851
SECTION 3
CIRCIUT DESCRIPTION
Change information, if any, affecting this section will be found at the rear of the manual.
Introduction
This section of the manual contains a description of the
circuitry used in the Type 7851. The description begins
with a discussion of the instrument using the basic block
diagram shown in Fig. 3-1. Then each circuit is described in
detail, using a detailed block diagram to show the intercon-
nections between the stages in each major circuit, and the
relationship of the front-panel controls to the individual
stages.
A complete block diagram is located in the Diagrams
Section at the back of this manual. This diagram shows the
overall relationship between all of the circuits. Complete
schematics of each circuit are also given in the Diagrams
Section. Refer to these diagrams throughout the following
circuit description for electrical values and relationship.
BLOCK DIAGRAM
General
The following discussion is provided to aid in under-
standing the overall concept of the Type 7851 before the
individual circuits are discussed in detail. A basic block
diagram of the Type 7851 is shown in Fig. 3-1. Each block
represents a major circuit within this instrument.
The Trigger Preamp circuit provides amplification for
the internal trigger signal. The internal trigger signal is re-
ceived from the Vertical Deflection System. The output
from this circuit is connected to the Trigger Generator cir-
cuit.
*DELAY MODE CONTROL
SWEEP INHIBIT
+T~
-T~
'---'I--L.-l-Lr-==--.l
Sweep """ISAWTOOTH SWEEP
I
1.J
Generator
JL
HOLDOFF
®
Trigger
Preamp
' - - - - - - - '
*Input only if Plug-In is
used as a Delayed Time-Base
Trigger I Sweep
Generator I Gate
....., r-
I
.--1----
LJ
DELAY GATE
Delay
.r
Pickoff ... DELAY CONTROL
~ Horizontal HORIZONTAL SWEEP
Preamp
Fig.3·1. Basic Block Diagram of the Type 7B51.
Indicator
Oscilloscope
+ GATE
3-1