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Transcript of Clocks
Engineering 1000 Clockworks Our Deconstructing of:
The Quartz Pocket Watch
(battery powered) Innovation Through the Years Because the pocket watch was so small we had to use rather
small and unusual tools. These consisted of tweezers, a thumbtack, a safety pin, a small magnifying glass, and a small eye glass flat head (screwdriver). Tools Used MATERIALS What are the materials in the Quartz watches
and why are they used?
Quartz is essential in these types of pocket watches because of piezoelectricity. Piezoelectricity is electrical current that flows through quartz when the pressure is applied (mechanical or electrical pressure). In pocket watches, electrical pressure from the small battery causes the quartz to carry current throughout the watch. Things We Found at First 1.5 volt Renata silver oxide battery model 377 swiss made. One of the most interesting things we have found
is the use of a plastic mold to hold everything within
the watch. It's easy to forget one of the most important
concepts behind every device, support. Flux Capacitors! But actually.. 8 1.5 volt silver oxide batteries inside Duracell and Energizer 12 volt batteries. What happens in a flux capacitor? It's made of two metal foils separated by a thin layer of insulating film. One foil is positive and the other
negative, with the insulator, creating an electric field. So what?
By creating an electric field it can store energy and transfer energy. So How Did We Take it Apart? It wasn't that hard! The screws used within the watch were
incredibly small, so we used the best tool possible, brute force.
We applied some pressure on the back of the screw at an angle
and propped them up. Why Copper? That's $3.38 /lb! Isn't this supposed to be cheap? Copper is a great conductor. Electrons
can move easily through the coils creating
a magnetic field. The system using the coils
is an inductor. Inductors resist change in the amount
of charge flowing through and can store energy. Relative to its more expensive conductive metal counterparts, copper is the best choice here. Gold-
Gold is used in electrical contacts
because it provides an electrically
conductive layer on top of copper.
Additionally, it is corrosive-resistant
which increases the watch's durability. Batteries? Nickel -
Nickel is usually placed in between the gold and the copper to create a buffer between the two metals. Without nickel atoms, the copper atoms will diffuse through the gold layer, resulting in a copper sulfate layer which can interfere with how the circuits work. The Mechanical Watch How it works? What has changed? So What Changes with a Quartz Watch? Quartz is the reason for the replacement of a tuning fork, keeping precise time with it's incredibly accurate frequency. But what about a quartz crystal maintains such an accurate frequency? Like most sands, quartz is made of silicon dioxide. Most solvents wont affect it and it can withstand hundreds of degrees Fahrenheit in crystalline form...hopefully that wont be necessary. In fact having a straight bar or disk shaped quartz crystal will increase precision. The bar shape oscillates at a low frequency which starts the crystal ringing. The output then converts into pulses suitable for the digital circuits. If a quartz crystal is bent it actually creates a charge or voltage on it's surface. What this means is if the crystal is shaped in the right direction to the axis it will have an oscillating voltage on its surface, and the rate of oscillation will be unaffected by temperature. Silicon -
Silicon is resistant to overheating, which is why it is used as insulation for electronic circuits. Also, silicon prevents electrical currents from sparking. It can be used to protect circuits from damage from static. Copper -
Copper is used in circuits because of its high conductivity and low cost compared to similar conductors like gold and silver. There are 5 elements to the mechanics of a wind up watch. First is the energy source, which in this watch (^ above) is a winding mechanism. It requires to be wound up daily and stores the energy in a mainspring.
Secondly there is the transfer of energy. A mechanical watch uses gears or wheels to transfer energy. Third we have an escapement, it is a device which keeps the wheels from "spinning out all of the energy at once." The escapement has steps which a pallet uses to lock and unlock the wheel. A forked lever pushes against an impulse pin to control the
locking and unlocking of the pallet. But what controls the impulse
pin? That's the fourth element, a balance assembly. It's swing controls the escapement. How can it move evenly with time? That's where the balance spring comes into play. The spring provides regular action. Lastly there is the time indicator. The face of the clock has a canon pinion which carries the minute hand, an hour wheel wheel which carries the hour hand, and a second wheel which you've can guess, carries the second hand. The big question of the day is what is the difference in
between a Quartz watch and a mechanical watch? The greatest
change has been the replacement of balance wheel and spring
with a tuning fork. But what is better than a tuning fork for
timing? A quartz crystal. Another huge change is the replacement
of the wind up device for the battery. The Crew Amy Hernandez PS ID #1935535 (Net ID: alh11018) Alyssa Weinstein PS ID #1953984 (Net ID: aew11008) Corbin Walsh PS ID #1917066 (Net ID: crw12002) Alex Berry PS ID #1916201 (Net ID: agb12001) Jay Latimer Chris Thai PS ID #1683033 (Net ID: cpt08001) The Reverse Engineering Project of EVERYTHING you could ever want to know about CLOCKS by 6 amazing (and particularly goodlooking) engineering students! A Breif History Of Time (pun somewhat intended) + The first pocket was invented in 1524 by Peter Heinlein, a locksmith in Nuremberg. 1500 + The first watches were incredibly inaccurate, and extremely bulky.
The inside were comprised of brass, and had no springs, which was a problem. + The first (more or less) accurate watch was created out of necessity.
+ Queen Elizabeth of England needed something for her Navy to accurately calculate longitude.+ John Harrison realized that in order to do that, you needed to know the time, so he created a reliable watch called the Harrison Marine Chronometer. The Crew members Alyssa and Corbin focusing in on the details. Yup. There's some real hands-on learning going on here. In case you were wondering: Yes, we did manage to chose the smallest possible item with that many concentric parts. The entire pocket watch was approximately 1 inch. Many a contact lenses were dried during the deconstruction of this project. 1915 + Around the turn of the century, Louis Cartier and Edmond Jaeger invented the first prototype of a men's wristwatch, for an aviator who wished to time flight performances without taking his hands off the wheel. By 1915, soldiers in the First World War used wrist watches to keep time while their hands were full. They were called "trench watches". 1960 + The accutron became the first tuning fork watch in 1960, developed by Bulova. + A Japanese watch company, Seiko, developed a watches using quartz chrystal as batteries, and developed the first quartz-crystal analog watch in 1969 + The wrist watch's origins began with the timepieces of 16th century Europe. They were fastened to clothing or worn around the neck like a necklace. Several inches in diameter, they were larger than today's wrist watches and only had an hour hand. Instead of a glass face, they often had a brass cover which was sometimes made with a grill-like design to allow viewing of the time without opening it, and they had to be wound twice a day. Because they were inaccurate and unreliable, they were more of a fashion statement than a true timepiece. 1700 + In1868 the first mechanical wrist watch even created. Constant Girard created a concept of a wrist watch for the naval officers of Germany. German Kaiser Wilhelm I ordered 2,000 watches to be produced. This was the first commercial production of wrist watches. 1868 + The self-winding wrist watch, or "kinetic watch", was invented in 1923. Just like that, the fashionable pocket watch faded into American history like top hats after John F. Kennedy. 1923 1969 . . . 2012 So where does that leave modern day time-keeping technology? ... Tuning fork watches use the resonance from a tuning fork within the watch to achieve the harmonic necessary to keep the watch ticking. Tuning Fork Watch We'll come back to this topic a little later... Now that you know how far watches have come,
it is time to move on to what we actually did Bibliography http://electronics.howstuffworks.com/gadgets/clocks-watches/quartz-watch.htm
http://www.madehow.com/Volume-1/Watch.html#b Automatic or Kinetic Watches Automatic watches function just like your average mechanical watch. However, it eliminates the need for winding. How? It relies on the user's natural wrist movements to spin a weighted roter. The router acts as the winding agent to wind the coils tight within the spring in the balance. A clutch attachment is added within the balance to stop the user from over-winding the watch. SIDE NOTE: Why Quartz?
Well, the heart of a quartz watch is a tiny sliver of made-made quartz. In a natural form, quartz is first loaded into a giant kettle or autoclave. Hanging from the top of the autoclave are seeds or tiny particles of quartz with the desired crystalline structure. An alkaline material is pumped into the bottom of the autoclave, and the autoclave is heated to a high temperature, dissolving the quartz in the hot alkaline liquid, evaporating it, and depositing it on the seeds. After about 75 days, the chamber can be opened, and the newly grown quartz crystals can be removed and cut into the correct proportions. The Future of Watches:
Well, we've had a good run analog clock, but the heavy classic analog clock is not practical anymore. Much like the clock's own predecessors, cellular phones and new age technology have made watches (like watches did pocket watches) obsolete. Watches are now worn almost exclusively as fashion statement pieces. Once the only way to keep track of time, these clocks are almost useless now. Battery, Capacitor and Inductor? We have an electrical Oscillator! Oscillators keep the clock moving at a constant frequency. The capacitor first releases some stored energy into the inductor which in turn will create a magnetic field. The inductor will keep the current going in the circuit and charge on plate of the capacitor. So that when the inductor's field is finished the capacitor is charged again. It goes in a cycle like this. Now let's talk physics. How do oscillators work? Capacitors and inductors of course. But what is the relationship? F is the frequency of the oscillator, L is the inductance in Henrys and C is the capacitance in farads. But what is capacitance and inductance? Capacitance is the electrical charge over voltage. C = Q / V. What is Q? Well the electrical charge can be defined as the current times the t. I X t = Q. And yes we know what voltage is, it is what the battery is giving the circuit (1.5volts for the watch). So again what is capacitance? C = (I X t) / V Now what is inductance? We can not just jump into this one unfortunately. First we have to look at two formulas for Emf or voltage generated. Emf = = -N( Δ(BA) / Δ(t)) Emf = -L ( I / Δ(t) ) This is Faraday's law. N is number of coils B is external magnetic field A is area of the coil L is inductance I is current t is time t is time BA = Φ magnetic flux so... -N( (flux) / Δ(t)) = -L ( I / Δ(t) ) or... L = N ( flux ) / I So what does inductance equal?
number of coils times the magnetic flux over current Now, let's go back to the first formula We can now define capacitance and inductance so let's find out what we need. (I(t)/V) X (N((flux)/I) (N((flux)t / V)) All we would need is the number of coils, the flux and the time to find out the frequency give by this oscillator. Luckily, there is only one capacitor and one inductor. PS ID #1925241 (Net ID: jvl11002)