By applying a constant voltage across R40+ P53, the Miller capacitor C51
will be discharged by a constant current as the base current of T55 is small .
.
A linear sweep will thus appear at the collector of T55 .
R43 and R44 (circuit diagram) are protection resistors which have no
influence on the basic . function. Discharging C51 continues for
a
full half
period.
The discharge is discontinued at the end of the half period when T56 opens
for a short mome11t and char
g
es · C51 to th� full ·s�pply' voltage . iB etween test
points T9 and T.10 a full-wave rectified · Sine..:wave is applied of which the
zero points opens T56. ·
·
The triggering circuit. T53 . supplies square wave pulses to the base of the
blocking osoillator .T5� }\Tith ,its transformer .Tr50.
The firing p:ulses are rectified by D52. and D58 and the positive firing pulses
are fed · to gates
SCRl
and · SCR2 via R5
"l and
R58 .
28
