Tektronix 576 - Page 60

DISPLAY
OFFSET
Substitutions
from Display
Amplifier Schematic
+

Ι L1
conducted by R
L1
1L2
conducted by R
L2
1 ρ conducted b y R ρ
impe d ance inputs are e q ual (1 s = 0) an d t hat the positioning
currents are une q ual
( ΙΡ 1 : A - ΙΡ2) .
From E q uation 3-1 the
loa d currents are found to be :
11_1 = IM - ID

(Equation 3-3)
1
L
2
=
1
Ρ2
- Ιρ

(E
q uation
3-4)
By subtracting E q uation 3-4 from Equation 3-3, it is
shown t hat the d
ifference in t he two loa d currents exactly
eq ual the d ifference in the two p
ositioning currents .
Fi g . 3-12 . Simplified sc he m at i c o f dis pl ay amplifier .
Circuit Description-Type 576
l L1
-
I L2
=
ΙΡ 1
-
I P2

(E q uation 3-5)
Since the p ositioning currents are n ot unequal,
the loa d
currents ( Ι
L l
and Ι
L 2)
are une q ual, which again changesthe
voltage p otential b etween t he d eflection p lates of the CRT .
These two examples
h ave shown that the voltage be-
tween the d eflection plates (an d t hus the position
of the
electron
beam as it strikes the face of the CRT) is con-
trolle d by two means,
the voltage app lie d to the h igh
impe d ance inputs and t he p
ositioning currents ap p lie d to
3- 1 9
V ertical
Amplifier
Simplified
Schematic
H orizontal
Amplifier
Q531A& Β QlA&
Β 0631 Α & Β
0533 Α & Β
02 Α & Β Q633A & Β
0560 Q3
Q660
Q569
04 Q669
0578 05
Q678
Q587 Q6
0687