- 1 (108.43 KiB) Viewed 19 times
a function of time (before
it switches to O for the first time).
b) After how much time will S switch to position O (for the
first time)?
c) At what (absolute) rate is the current changing immediately
after this first switch?
d) Give an expression for the current as a function of time
after this first switch.
e) What is the current when S switches back to the position
I?
f) Give an expression for the current as a function of time
after this second switch.
g) Calculate the average current in one cycle.
平 11 Problem 1 A Self-Triggering Oscillator R L The adjacent circuit contains an ideal 0 elle battery with emf E = 48 V, a resistor heat with resistance R = 33 N, and a coil (inductor) with self-inductance E L=64 H. Initially, there is no current in the circuit. The switch Sis temper- S ature-dependent: it switches to posi- tion O when it is warm, and back to I when it has cooled down. In the circuit, the switch responds to the heat developed in the resis- tor. At time t=0 the switch S is thrown to position I (“battery on”). When the current in the re- sistor exceeds i ip = 1.2 A the switch temporarily switches to position 0 (“battery off”), bypass- ing the battery. After a time duration Atcooi = 1.7 s the switch has cooled down enough to switch back to position I, reconnecting the battery to the circuit. The switching time of Sis negligible. The switch uses a "make-before-break” mechanism.