Without the benefit of 60 Hz line voltage input, 1 pulse per second clock frequency could be generated by:
A) a 555 timer and Schmitt- trigger.
B) a crystal oscillator.
C) a Schmitt- trigger and MOD 60 counter.
D) Either A or B

Question

Quizplus · Accepted Answer

Both a 555 timer with a Schmitt trigger and a crystal oscillator can be used to generate a 1 pulse per second clock frequency. The 555 timer can be configured to produce a variety of frequencies including 1 Hz, and a crystal oscillator can be precisely cut to oscillate at nearly any desired frequency, including 1 Hz.

Without the Benefit of 60 Hz Line Voltage Input, 1