Deck 36: The 555 Pulse Timer

Question 1

In the accompanying figure, when capacitor C1 is charged to two-thirds of Vcc, the output turns off,  which turns off relay ____.

A) R1
B) K1
C) D1
D) S1

Answer 1

B

Question 2

In the accompanying figure, pin #2 is connected to pin #6, which is at ground potential.

Answer 2

True

Question 3

In the accompanying figure, once capacitor C1 has been charged, it is prevented from discharging  through resisters R3 and R4.

Answer 3

False

Question 4

In a 555 circuit used as a pulse timer, the capacitor is charged by the Vcc and not from a feed-back  circuit from the output of the timer.

Question 5

When used as a pulse timer, the 555 timer is connected differently than the 555 timer that is used as an  oscillator.

Question 6

In the accompanying figure, diode D2 is a ____ diode.

A) stealing
B) free-wheeling
C) blocking
D) locking

Question 7

In the accompanying figure, diode D1 is used as a ____ diode.

A) stealing
B) locking
C) blocking
D) free-wheeling

Question 8

In the accompanying figure, transistor Q2 is used to turn relay coil K1 on or off.

Question 9

In the accompanying figure, resistor ____ limits the current to the base of the transistor Q1.

A) R1
B) R2
C) R3
D) R4

Question 10

In the accompanying figure, capacitor ____ is charged by a feedback circuit from the output of the  timer and not from Vcc.

A) D1
B) C1
C) R1
D) S1