What's the difference between Mechanical and Quartz Watch Movements?
Understanding Different Types of Watch Movements
Choosing a wristwatch can be daunting to some, however, understanding the main mechanical differences with a touch of history, can certainly help. When considering any timepiece, thinking about the type of movement that's driving the watch, is a good start. The movement in a watch is much like the engine in a car. It may be hidden from view, but is the most critical part. The two main types of watch movements are Mechanical and Quartz.
While outwardly it may be difficult to differentiate between the two, they actually work very differently and bear little resemblance other than the fact they both tell the time on your wrist. It comes down to the first step used in every timekeeping device - what is being used as a measure of a passage of time. For example, one of the earliest clocks is the sundial. In this case, the measured subject is the position of the sun which is then translated to a shadow. Much later, we started using pendulum clocks that will measure the swing of the pendulum which is then translated to the hands and dial. Though the pendulum clock shares a lot more in common with mechanical wristwatches than a sundial, the size of a mechanical watch demands yet another system to measure time.
Mechanical Watch Movements
Mechanical movements can be subdivided into two categories. Manual-wind and automatic. The underlying principle is the same but differs in how they maintain power. In all mechanical watches, a balance wheel and spring are used. The wheel oscillates at a consistent rate using the force of a spring as it winds and unwinds. This creates a back and forth motion which may be compared to the movement of the pendulum.
In order for this mechanism to work continuously, the spring needs to be wound periodically. In early watches, this was done manually, using what's called, the crown. The first self winding mechanism design goes as early back as 1776, when Abraham-Louis Perrelet created a pocket watch that was reported to fully wind from 15 minutes of walking. This led to a number of notable historical figures in horology including Abraham-Louis Breguet, to invent further examples using different methods such as the 'side-weight' and 'centre weight' designs. The first commercially available wristwatch that incorporated an automatic mechanism were called 'bumpers' and were invented by British watch repairer, John Harwood. In this particular design, the movement of the wrist would spin a weighted rotor, which would turn a ratchet thereby winding the spring. This design is used to this day though has significantly evolved to a higher functionality standard and including an improved durability. Despite needing far less manual winding, its still required somewhat to kickstart or maintain the movements power. Preference to the automatic movement will likely be about practicality as it won't require constant winding. It also saves wear and tear caused by the need for constant winding. For the manual movement, its generally about the look as it doesn't have a winding rotor to conceal viewing of the movement, though others may simply enjoy that moment of winding.
You may be wondering what a crystal has anything to do with clockwork. Well, the answer lies in the unique nature of the quartz crystal, discovered in the 1950s. When an electrical current is applied, the crystal will vibrate at its resonance frequency, essentially making it an oscillator. In watches, this oscillation can be harnessed for timekeeping, thus replacing the role of the balance wheel and mainspring.
The quartz movement itself is much like other electronic devices visually in terms of its architecture and contrasts greatly to mechanical movements which are brimming with tiny moving bits and pieces. What this also means is they eliminate the difficulties associated with mechanical movement manufacture and assembly, and ultimately lowering the price of watch production. Aside from being less costly to produce, the quartz watch has a super advantage, maybe even the ultimate advantage in the business of measuring time and that's it’s superior time-keeping accuracy. These days, well built mechanical watches may be extremely accurate, losing or gaining just a few seconds per day. However, the quartz watch can be accurate within a few seconds per year.