Simplified Diagram Of The Dc Restorer Circuitry - Tektronix 2246 1Y Service Manual

Theory of Operation—2246 1Y and 2246 Mod A Service
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Figure 3-6. Simplified diagram of the DC Restorer circuitry.
The charge held by C2711 sets the control-grid bias
voltage. If more charge is added to that already
present on C2711, the control grid becomes more
negative (display dim m er).
charge is added, the control-grid voltage level
becomes closer to the cathode-voltage level, and
the display becomes brighter. During periods that
C2712 is charging, the crt control-grid voltage is
3-40
C2711
Conversely, if less
-2700
held constant by the long tim e-constant discharge
path of C2711 through R2724.
Fast-rise and fast-fall transitions of the Z-Axis out­
put signal are coupled to the crt control grid through
C2711 to start the crt writing-beam current toward
the new intensity level. The Dc Restorer output level
TO CRT
GRID
6081-09