The document discusses the history and workings of the pendulum clock. It describes how Galileo first conceived of using a pendulum to measure time in the early 1600s. Christian Huygens is credited with inventing the first pendulum clock in 1656. The document then explains how pendulum clocks work, including how the swinging pendulum regulates the gear train and causes the hands to move at a steady rate. It also discusses different types of pendulum clocks and provides conclusions about the history and human understanding of time.

1. Pendulum Clock’s
Presented To:
Sir Arshad Subhani
Presented By:
Malik Ghulam Murtza
Class/section:
(B.C.S/1ST SEMESTER)/B
Roll No:
9226
DEPARTMENT OF COMPUTER SCIENCE
GARRISON POSTGRADUATE
COLLEGE [M]

2. Scheme of Presentation
 The history of time
 History of pendulum clock
 What is pendulum clock
 How pendulum clock work’s
 Types of pendulum clock’s
 Brief discussion on pendulum clock’s
 Uses of pendulum clock’s
 Conclusion
 References

3. The history of time
(before pendulum clock)

4. Augustine and time
• Time as the dramatic marker of
being human
• Several ways to conceptualize time:
• The ‘time-lessness’ of God
• The time of humans, something that
cannot be fully comprehended and
that connects the inside/outside
• The measuring of time does NOT
mean understanding time, but as
humans this is the best we can do

5. Starting to measure time: the
sunclocks

6. Athanasius Kircher’s sunclock

7. 11th Century in China: the Su-Sung
(waterclock)

8. 14th century Europe: church-clocks,
no minutes
Clock in the Salisbury Cathedral, 1386

9. History of pendulum clock

10. Galileo and Huygens: the study of
the pendulum

11.  Galileo is credited with coming up with the concept of
a pendulum as an tool for measuring time, having
studied its motion as early as 1582. Although he drew up
design plans for a pendulum clock, Galileo died in 1642
before he could actually build one.
 Dutch mathematician and astronomer Christian
Huygens is the man who is actually credited with the
invention of the pendulum clock, in 1656.

12. Christian Huygens and the pendulum
clock (ca. 1650s)
• The pendulum swings left and right,
and as it swings, it turns a wheel
with teeth. The turning wheel turns
the hour and minute hands on the
clock
• On the first pendulum clocks, the
pendulum used to swing a lot (about
50 degrees). As pendulum clocks
were improved, the pendulum
swung a lot less (about 10 to 15
degrees)
• The first pendulum clock with
external batteries was developed

13. Pendulum clock

14. What is pendulum clock

15. 1) A pendulum clock is
a clock that uses a pendulum,
a swinging weight, as its time-
keeping element.
‘Or’
2) A clock regulated by a pendulum.
 First pendulum clock of the world
 (Pendulum clock conceived by
Galileo Galilee
around 1637. The earliest known
pendulum clock design, it was
never completed)

16. How pendulum clock works

17. How pendulum clock works
(1)
 Introduction
There is a pendulum that is
shown inside. this is the
mechanical pendulum
clock.

18. How pendulum clock works (2)
Parts of Pendulum clock
 Parts of Pendulum clock
• Pendulum clocks have been used to keep time since
1656, and they have not changed dramatically since
then:
(1)There is the face of the clock, with its hour and minute
hand (and sometimes even a "moon phase" dial).
(2)There are one or more weights (or, if the clock is more
modern, a keyhole used to wind a spring inside the clock
-- we will stick with weight-driven clocks in this article).
• And, of course, there is the pendulum itself.
• In most wall clocks that use a pendulum, the pendulum
swings once per second. In small cuckoo clocks the
pendulum might swing twice a second. In large
grandfather clocks, the pendulum swings once every two

19. How pendulum clock works (3)
A Weighty Subject
 A Weighty Subject
• The idea behind the weight is to act as an
energy storage device so that the clock can
run for relatively long periods of time
unattended. When you "wind" a weight-driven
clock, you pull on a cord that lifts the weight.
That gives the weight "potential energy" in
the Earth's gravitational field. As we will see in
a moment, the clock uses that potential energy
as the weight falls to drive the clock's
mechanism.

20. How pendulum clock works (3)
A Weighty Subject
So let's say that we wanted to use a falling
weight to create the simplest possible clock
-- a clock that has just a second hand on it.
We want the second hand on this simple
clock to work like a normal second hand on
any clock, making one complete revolution
every 60 seconds. We might try to do that,
as shown in the figure on the right, simply
by attaching the weight's cord to
a drum and then attaching a second hand
to the drum as well.

21. How pendulum clock works (3)
A Weighty Subject
• This, of course, would not work. In this
simple mechanism, releasing the weight
would cause it to fall as fast as it could,
spinning the drum at about 1,000 rpm until
the weight clattered on the floor.
• Still, it's headed in the right direction. Let's
say we put some kind of friction device on
the drum -- some sort of brake pad or
something that would slow the drum down.
This might work. We would certainly be
able to devise some scheme based on
friction to get the second hand to make
approximately one revolution per minute.
But it would only be approximate. As the

22. How pendulum clock works (3)
A Weighty Subject
• Property of pendulum
The period (the amount of time it takes for a pendulum to go
back and forth once) of a pendulum's swing is related only to
the length of the pendulum and the force of gravity. Since
gravity is constant at any given spot on the planet, the only
thing that affects the period of a pendulum is the length of
the pendulum. The amount of weight does not matter. Nor
does the length of the arc that the pendulum swings through.
Only the length of the pendulum matters.

23. How pendulum clock works (4)
Experement
If you not convinced from previous discussion then I
would like to perform a experiment as:
Experiment Time:
As we stated on the previous page, the only thing
affecting the period of a pendulum is the length of that
pendulum. You can prove this fact to yourself by
performing the following experiment. For this
experiment you will need:
• A weight
• A string
• A table
• A watch with a second hand (or a numeric seconds
display on a digital watch)

24. How pendulum clock works (4)
Experiment
For the weight you can use
anything. In a pinch, a coffee mug
or a book will do -- it doesn't really
matter. Tie the string to the weight.
Then suspend your pendulum over
the edge of the table so that the
length of the pendulum is about 2
feet, as shown inside:

25. How pendulum clock works (4)
Experiment
Now pull the weight back about a foot and
let your pendulum start swinging. Time it
for 30 or 60 seconds and count how many
times it swings back and forth. Remember
that number. Now stop the pendulum and
restart it, but this time pull it back only 6
inches initially so it is swinging through a
much smaller arc. Count the number of
swings again through the same 30- or 60-
second time period. What you will find is
that the number you get is the same as the
first number you counted. In other words,
the angle of the arc through which the
pendulum swings does not affect the

26. How pendulum clock works (4)
Experiment
Once someone noticed this fact about
pendulums, it was realized that you could
use the phenomenon to create an
accurate clock. The figure below shows
how you can create a
clock's escapement using a pendulum.
In an escapement there is a gear with
teeth of some special shape. There is
also a pendulum, and attached to the
pendulum is some sort of device to
engage the teeth of the gear

27. How pendulum clock works (4)
Experiment
One thing to keep in mind is that
pendulums will not swing
forever. Therefore, one
additional job of the escapement
gear is to impart just enough
energy into the pendulum to
overcome friction and allow it to
keep swinging as shown in
figure again:

28. How pendulum clock works (4)
Experiment
• So, let's say that you create an escapement. If you gave the
escapement gear 60 teeth and attached this gear directly to the
weight drum we discussed above, and if you then used a
pendulum with a period of one second, you would have
successfully created a clock in which the second hand turns at
the rate of one revolution per minute. By adjusting the
pendulum's length very carefully we could create a clock with
very high accuracy.
• However, while accurate, this clock would have two problems
that would make it less-than-useful:
(1)Most people want a clock to have hour and minute hands as well.
(2)You would have to wind the clock about every 20 minutes.
Because the drum makes one revolution every minute, the
weight would unwind to the floor very quickly. Most people would
not like a clock that had to be rewound every 20 minutes!

29. How pendulum clock works (5)
Gearing Up!
• The problem of having to rewind every 20 minutes is easy to solve.
you can create a high-ratio gear train that causes the drum to make
perhaps one turn every six to 12 hours. This would give you a clock
that you only had to rewind once a week or so. The gear ratio
between the weight drum and the escapement gear as shown in the
diagram below:

30. How pendulum clock works (5)
Gearing Up!
You can see that, even though all the gears in a clock make it look
complicated, what a pendulum clock is doing is really pretty simple.
There are five basic parts:
• Weight or spring - This provides the energy to turn the hands of the
clock.
• Weight gear train - A high-ratio gear train gears the weight drum way
up so that you don't have to rewind the clock very often.
• Escapement - Made up of the pendulum, the anchor and the
escapement gear, the escapement precisely regulates the speed at
which the weight's energy is released.
• Hand gear train - The train gears things down so the minute and hour
hands turn at the right rates.
• Setting mechanism - This somehow disengages, slips or ratchets the
gear train so the clock can be rewound and set.

31. Types of pendulum clock’s

32. Types of pendulum clock’s
No : Type of pendulum clock’s No: Type of pendulum clock’s
1 Musical pendulum clock 2 Ignatz flying pendulum clock
3 Horolover flying pendulum
clock
4 Crazy flying pendulum clock
5 LEGO pendulum clock 6 Phun pendulum clock
7 Paper pendulum clock 8 Panthoen pendulum clock
9 Swinging pendulum clock 10 Rotary pendulum clock
11 Hangman pendulum clock 12 Warriors pendulum clock
13 Home made LED pendulum
clock
14 Weird pendulum clock
15 Beuco pendulum clock 16 Elvis pendulum clock
17 Charlie chaplin pendulum
clock
18 Bernoux conical pendulum clock
19 Small bentima pendulum 20 Vortex pendulum clock

33. Conclusion!

34. oFrom Augustine’s reflections on time:
oTime as the dramatic marker of being
human
oTime is fundamentally impossible to
comprehend, but…
oIt can be measured!
oHistory of measuring time
oIn a sense, time is a HUMAN creation
oRelationship between human and
technology as an important aspect of
the ‘history of time’

35. References!

36. The major source of collection of this data is collected
through INTERNET through following web sides:
o WWW.Answer.com
o WWW.Wikipedia.com
o WWW.Webopedia.com
o WWW.Webanswers.com
o WWW.How stuff work?.com
o WWW.mypptsearch.Ppt search engine
o WWW.mypdfsearch.Pdf search engine