Tektronix Webcam 070-8030-01 User Manual

Theory of Operation

1780R-Series Service Manual

This diagram contains the interface to the front-panel switches, indicators, and
touch panels along with the rear-panel serial and remote connectors. In addition,
it contains circuitry that controls internal switching functions and generates
readout for both CRTs.

This diagram contains the blanking and unblanking functions of the CRTs, their
power supplies and display control circuits, cursor implementations, and the low
voltage power supply circuitry.

Schematic diagrams for this instrument are grouped both functionally and by
etched circuit board. One major exception occurs with Schematic 3, which
contains probe circuitry. Probe input is on the Vectorscope circuit board
(Assembly A6) while the probe output amplifier and DC restorer circuits are on
the Waveform circuit board (Assembly A2).

The individual circuit description write ups are separated by schematic diagram
number. In some cases more than one diagram is represented by a circuit
description. In those cases the description title indicates which diagrams are
included.

Each description is preceded by a block diagram which serves to introduce each
new group of circuits, showing their interconnections. In addition to the
interconnection of circuit blocks these illustrations also give the key circuit
numbers associated with each represented circuit. Having these numbers on the
block diagram makes it easy to locate the key components on the diagram.

A short overview of the block is provided to help provide an overall insight into
each schematic diagram. The overview does not get too specific, it is only
intended to functionally introduce the schematic diagram.

The circuit theory which follows the overview is more detailed and contains
circuit numbers to locate specific components. (In the event a circuit number can
not be found, there is a component location chart associated with each diagram
that gives grid locations similar to those used on a road map.)

Most of the diagrams in Section 9 have circuit block titles printed on them.
These titles serve as both paragraph headings in the circuit theory and as block
names on the introductory block illustrations.