Page 12 - Template EBook Kita (A4 Document)

TOPIC 1: INTRODUCTION TO 555 TIMER

WHAT'S IN A 555 TIMER?

1 voltage The voltage divider is made using

three 5k resistors. The voltages
divider
across these resistors are given as
reference

comparators. voltages to the

Upper comparator: The inputs to the

upper comparator or the threshold
comparator are the threshold pin

connected to the non-inverting input

(+), and a reference voltage of 2/3 Vcc

is connected to the inverting input (-)
2 comparator
of the comparator.

Lower comparator: For the lower
comparator or the trigger

comparator, 1/3 Vcc reference

voltage is given to the non-inverting
input (+) and the trigger pin is

connected to the inverting input (-)

of the comparator.

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