Tektronix 5110, Инструкция по эксплуатации

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Circuit Desert ption-5110
Vertical Amplifier
The Vertical Amplifier circuit provides approximately
10X amplification of the vertical signal before passing it to
the vertical deflection amplifier in the display unit. The
Vertical Amplifier consists of Q650,
Q658, Q660, Q668,
and their associated passive components, connected in a
differential configuration. The output signal is in phase
with the output of the vertical plug-in.
Horizontal Amplifier
The Horizontal Amplifier consists of Q670, Q678, Q680,
Q688, and their associated passive components. The
circuit is nearly identical to the Vertical Amplifier just
described. It receives a push-pull input directly from the
horizontal plug-ln compartment via contacts A7, A13, B7,
and B13 of J603. The two halves of this amplifier are
balanced in the quiescent condition by adjustment of
R675, Hor. Cent. The output of the Horizontal Amplifier is
sent to the horizontal deflection amplifier.
AUXILIARY BOARD
An auxiliary board plugs into J604 on tne Interface
circuit board, and becomes part of the Interface circuit,
The single-beam auxiliary board accepts the push-pull
signal outputs from both vertical plug-ins. Emitter
followers Q701, Q703, Q711, and Q713 provide a high-
impedance input to two pairs of grounded-gate FET
amplifiers, Q702-Q704 and Q712-Q714. The switching
circuit consists of Q721 and Q722, connected as a
comparator. Plug-in "on" logic levels are applied to the
switching circuit in addition to the switching signal from
the Countdown circuit. The switching circuit permits only
one pair of amplifiers to be on at a time, thus permitting
only one of the two vertical plug-in signals to pass to the
Vertical Amplifier. In the chopped switching mode, the
switching between pairs of amplifiers occurs at a 50-
kilohertz rate (switching occurs on both the negative- and
positive-going transition), and in the alternate mode,
switching occurs at the end of every second sweep. If no
"on ” logic level is applied to the switching circuit from
either vertical plug-in, Q702 and Q704 will remain on,
passing any signal from the left vertical plug-in.
VERTICAL AND HORIZONTAL
DEFLECTION AMPLIFIERS
Vertical Deflection Amplifier
The Vertical Deflection Amplifier provides the final
amplification of signals applied to the vertical plug-in
units. It produces a push-pull output sufficientto drivethe
ert
vertical deflection plates. The amplifier consists of
Q104, Q106, Q114, and Q116, connected in a differential
configuration.
The input signal arrives via P612 from the Interface
circuit. The output signal is developed across the
collector-load resistors, R104 and R114, and is about 50
times the magnitude of the input signal. Resistor R116 Vert
Gain, provides Q106-Q116 emitter degeneration tosetthe
gain of the stage to provide a calibrated vertical display.
Horizontal Deflection Amplifier
The Horizontal Deflection Amplifier consists of Q124,
Q126, Q134, and Q136, and is basically the same as the
Vertical Deflection Amplifier just described. It provides
final amplification of signals from the horizontal plug-in
unit, which arrive via P6II. The gain of the stage is set by
Hor. Gain R136to provide a calibrated horizontal display.
Beam Finder
If a high-amplitude signal or a misadjusted control has
deflected the trace or display off screen, it can be located
by pressing the front-panel BEAM FINDER pushbutton.
This opens S125, allowing current through R125 into the
emitter
circuits of both deflection amplifiers. R125 limits
the current available to the transistor, and hence, to the
collector-load resistors. Thus, the dynamic range of the
deflection plates is limited to an on-screen level, and the
display is compressed within the viewing area.
Also, when the BEAM FINDER switch is pressed, the Z
Axis Amplifier in the ert circuit senses the slight increase
in voltage level at the R108-R118-R128-R138 junction. The
Z Axis Amplifier produces a slight increase in ert beam
intensity, allowing the trace to be displayed even though
the INTENSITY control may be fully counterclockwise.
X-Y Phasing
Variable capacitor C116, Phase, is connected across
the input emitters of the Vertical Deflection Amplifier. This
capacitor is adjusted to eliminate the inherent phase
difference between
the vertical and horizontal deflection
systems when operating in the X-Y mode.
CRT CIRCUIT
The ert circuit produces the high-voltage potential and
provides the control circuits necessary for operation of the
cathode-ray tube (ert). This circuit also includes the Z-
Axis Amplifier stage to set the intensity of the ert display.
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