Fig. 1 .. Circuit to illustrate principle of operation of the push-pull
output system. The grids are driven out of phase, and the a-c load
currents add while the d-c load currents subtract.
PHASE- INVERTER
DRIVER
Fig. 2
-
I
OUTPUT
STAGE
Method of driving output stage by a phase inverter. Each of the output tubes i s driven from grid
to cathode.
- \lethod of supplying propzr screen v c i t a g e s f o r bem.paurzr tubes. ??le d-c s c r e e n c u r r e n t s
v!indings i n the opposite sense
so t h a t t h e r e i s no n e t d - c flux from the screen cumen0s.
Fig. 3
Fig. 4 - L'p>er t r x e i s the rraveforn of theoutput
v o l t a g e f o r t h e c i r c u i t of Flg. 3 , and thelower
t r a c e i s che cathodecurrent i n t b e lower tube.
B o t h t r a c e s :were obtained a t a S+wat,t power l e v e l
and at. 20 k c .
flow throughthe
two
F I RST
STAGE
1
I
P H A S E - INVERTER
DRIbER
I
l
OUTPUT
STAGE
Bt
__o
B__o
Fig. 5 - C i r c u i t t o i l l u s t r a t e
onemethod
of applyingfeedback.
Thefeedback
is taken from t h e j u n c t i o n
cathode of t h e f i r s t s t a g e .
of t h e two o u t p u tt u b e st ot h e