No sales tax except for Nevada residents

Understanding How Digital Clocks Work

Understanding How Digital Clocks Work

From the alarm clock on your bedside table to the giant wall clock at your gym, digital clocks are becoming more and more ubiquitous in our technologically advanced world. But have you ever stopped to wonder how they work? What’s behind these pieces of time-telling technology that we use every day? Here is a guide that will make understanding how digital clocks work simple and informative.

Components of a Digital Clock

A digital clock is made up of the same basic components as an analog, pendulum clock. Here are the four main parts that every digital clock needs to work properly.

Power Source

Every clock needs a power source to function. Digital clocks operate using electronic power, either from a battery or from the AC power that a wall outlet supplies. Because they are portable, digital wristwatches use a battery, while a digital wall clock would generally use an outlet. A digital alarm clock can be powered with either type of source.

Time Base

The time base of the clock is the part that accurately pulses and keeps time. Because their time bases are electronic, digital clocks don’t audibly tick, but if they did, the time base would be the part ticking, counting the seconds as they pass by.


The counter in a digital clock counts the pulses that the time base produces and registers a numeral time. The electronic counter in a digital clock is equivalent to the gears that move the hands of an analog clock.


The display of a digital clock shows the time that has been calculated by its other parts. Digital clock displays use either Light Emitting Diodes (LED) or Liquid Crystal Display (LCD) to light up the numerals on the display.

How a Quartz Clock Works

Now that you know each of the four major components of a digital clock, let’s focus on one of the most common types of digital clocks—a quartz clock.

How They Generate Oscillations

The first step to understanding how digital clocks work is understanding oscillations, including how and why they are produced. The function of a digital quartz clock centers around a small quartz crystal inside of the clock. Quartz is used rather than a different material because its molecular structure is uniform, resulting in consistent vibrations that can effectively mark the constant passing of time. When an electric charge from the clock’s battery or another power source passes through the crystal, it vibrates back and forth, or oscillates, at a set frequency of 32,768 times per second. For every 32,768 oscillations of the crystal, a circuit in the clock, called a counter circuit, counts one second. The circuit then releases one electric pulse for each second detected based on the crystal’s oscillations.

How Oscillations are Translated To a Digital Display

Now you know how digital clocks oscillate and accurately keep track of the passing seconds. But once the clock creates and registers this information, how are the seconds that are counted then translated into the time you see on the display of your digital clock? In an analog quartz clock, the electronic pulse given off by the circuit powers a small motor that moves the gears, which move the hands of the clock. But digital clocks don’t have the mechanical elements that analog clocks do; in a digital clock, rather than powering the gears of a clock, the electrical pulse is processed by a series of electronic components.

A digital clock’s quartz crystal oscillates 32,768 times per second, and by using mathematical calculations and counters, the number of oscillations is divided to create a 60 Hz oscillation pulse. Each time the counter circuit counts the crystal’s oscillations and releases an electric pulse, the pulse is converted to a binary number, so that the 60 Hz oscillations are further divided, resulting in a 1 Hz pulse that can accurately track seconds. In this way, a microchip converts the binary numbers into seconds, minutes, and hours.

Once the counters have calculated the seconds, minutes, and hours, the information is transferred to the LED or LCD screen of the clock. Each digit on this screen is made up of seven segments that can light up to display the various numbers; this display is called a seven-segment display. A microchip, called a binary number to seven second display converter, reads each binary number it receives from the counters and turns on the appropriate segments to create each number on the screen. So, for example, if the digit on the screen was a one, two different segments on the screen would light up to create the digit. But if the digit were an eight, all seven segments would light up to form the number. When the time on a clock reaches 12:59, a microchip inside the clock registers the number thirteen when the hour changes and knows to set the clock back to 1:00.

Why Do Clocks Lose Time?

Although digital clocks, including quartz digital clocks, are very accurate, they can lose or gain a small amount of time as time passes. The amount of time gained or lost usually only adds up to seconds or minutes each year and is not enough to be terribly noticeable. Clocks lose or gain time due to inconsistencies in the vibrations of an oscillator. These inconsistencies are caused by changes in temperature and air pressure that cause the oscillator to vibrate slightly faster or slower than its usual speed. Even with these slight variations, digital clocks are still incredibly accurate at telling time.

From looking at a digital clock from the outside, you would never inherently know about all the mechanisms inside it that result in the numbers you see on the clock’s screen. Understanding how digital clocks work will make you more appreciative of these bits of technological genius in your life—like digital clocks themselves—that we all tend to take for granted. And the technology of clocks is still advancing—timekeeping technology is being used in more products, and more and more features are becoming available in digital clocks.

Here at BigTimeClocks, we prioritize incorporating the latest and greatest technology into our LED countdown clocks and other products. If you are looking for a well-made digital clock with the latest features, check out our inventory today.

Understanding How Digital Clocks Work