W h e n sw itc h 1 is closed, c a p a c ito r 4 is charged b y a d-c power source
th r o u g h series-connected resistor 3. The tim e re q u ire d to charge c a p a c itor
4 depends u p o n its c a p a c ity a n d the resistance of resistor 3. W h e n the
c a p a c ito r v o lta g e reaches a de fin ite n e g a tiv e v a lu e , tu b e 5 is b lo c k e d , the
p late curre nt drops to zero a n d r e la y 6, connected in to th e p la te c irc u it
of the tu b e , releases the a rm a tu r e of the re la y , o p e n in g its co n ta c ts at b rid g e 7.
$4334$SmE,Re$