Digital watch is a type of watch with digital display and is popular due to its convenience and accurate way to tell time. But how does it actually works?
So how do digital watches work? Digital watches work similar to quartz watches using electronic-quartz oscillation timekeeping with digital displays to show the time.
The inner workings of a digital watch can be broken down into these 3 main components:
1. Source of Power
The source of power for a digital watch is electric and can either be from a battery cell or an AC power. This depend on the watch itself and each have its own advantages and disadvantages.
For an AC powered digital watch, it’s mainly used for wall or permanent clocks which is not designed to be moved around.
This type of watch has the advantage of not having to change out its battery periodically as the power is directly supplied from the home’s power supply. It’s also usually used for bigger sized watch/clocks that will need a lot of electricity to run (more than what a normal battery cell can give).
In comparison, the battery powered watch will need periodic battery cell replacement. Due to its limited electric charge, it’s also limited to only smaller sized watches and not for big giant clocks. It’s best advantage is the ability to be mobile (which is the case with digital wristwatches and small alarm clocks). Since the power supply is also independent, any power outage to your home will not affect the watch.
The choice of battery or AC power operated watch will depend on what you want the watch to have. For example, if it’s a simple wristwatch or wall clock, then a battery powered one is sufficient to power the watch. But if the watch you need has more functions such as an integrated radio for instance, then an AC power will be more suitable in this case.
2. Timekeeping Mechanism
All digital watches uses an electronic timekeeping mechanism by utilizing an integrated circuit/microchip inside it. But there are 2 different oscillators that digital watches usually use: a quartz crystal oscillator or using the AC power frequency.
The oscillators are the heart of any watch because it’s the timekeeping mechanism that will tell the watch what is the definition of “1 second”. From there, the watch can do its job by stepping up its counter to count minutes, hours, days etc. In short, the oscillators is the one thing that keeps time in a watch.
The first type is using the AC power own frequency which is 50 or 60 Hz. The watch (usually one that requires a plugged in power) will then use this signal and divides it a few times until it has 1 signal per second (or 1 Hz). From then on, the watch can use this signal for its timekeeping.
The second type is using quartz crystal oscillator, much like how a quartz watch works. Inside the watch is a very small quartz crystal (or just a grain of sand/silica) that is shaped into a tuning fork. Now, quartz is a piezoelectric material in which it will vibrate when electricity passes through it (and vice versa).
The watch will pass electricity to the quartz and it will vibrate, to the tune of 32,768 Hz. This vibration will be detected as a signal and it will be divided until it equals 1 signal per second. The final signal from the timekeeping mechanism will be transferred to the time display.
3. Digital Time Display
There are 3 main types of digital display: mechanical-digital display, 7-segment digital display and modern digital display. Let’s look at each of them.
The first type of digital watch is the mechanical-digital display. It’s a display with numbers but the numbers are changing mechanically (kinda like how the date changes in a normal watch). It’s one of the first types of digital watches produced and is quite rare today because the other 2 types of displays are more efficient and cheaper to produce.
The second type is the 7-segment digital display. I’m sure you will recognize the older type of digital displays with a fixed black bars. This can change depending on the numbers to be displayed simply by blackening out the bars as needed. It’s one of the most widely used digital display for watches nowadays.
The last type is the modern digital displays using LCD (liquid crystal display) or LED (light-emitting diodes). This display can be seen on many smartwatches where the watch uses a more advanced and nicer looking display. The numbers on this type of display is also easier to be understood as it’s not as “blocky” as the 7-segment digital display. In addition, these displays typically has colors which make it more attractive to look at.
The main advantage of digital display on watches is how easy it is to tell time. Our brain can register time faster by looking at numbers (on a digital display) compared to the classic analog 3-hands watch. This one advantage is a great one especially for those that needs to be able to tell time as fast as they can.
What Is Digital Watch Made Of?
Most of the digital watches nowadays uses plastic as its main components, especially for the outer case. Plastic is a great material as it’s cheap and can be formed into various shapes. It’s also sturdy and is very light. There are also more expensive digital watches that use stainless steel or aluminum as its case material (case in point, the Apple watches).
The internal components of the watch is the typical electronic stuffs: microchips, battery, wires and so on. The microchip is usually made of silicon while the LED display can be made of gallium phosphide or other materials.
The material for the strap is more conventional with the use of rubber, steel or leather bands (all the kind of stuffs already available on most watches).
Related Questions
How do you program a digital watch? Programming a digital watch can be done by going to the time setting mode and change its time. As this will largely depend on the type of watch used and settings available, it’s recommended to read the user manual or watch a YouTube video on how to set the time for your specific digital watch.
What was the first digital watch with LED display? The Pulsar was the first digital wristwatch with LED display and was introduced in 1970. It’s one of the watches from Hamilton and was also featured in Stanley Kubrick movie 2001: A Space Odyssey.
I hope this article about how digital watches work is beneficial to you. Do let me know if you have questions or comments on it by commenting below.
Cheers!