There frequency is an essential aspect in the operation and performance of automatic watches. It determines the stability of the movement, the accuracy of the displayed time and the energy efficiency of the wristwatch.

In this article, we will explore the meaning of frequency in automatic watches, its impact on quality and performance, and the different frequency values ​​that can be found in watch mechanisms.

What is frequency in an automatic watch?

Frequency refers to the number ofalternations (oscillations) that the movement of the pendulum performs in a given unit of time. It is generally expressed in alternations per hour (A/h) or in Hertz (Hz). An alternation corresponds to a complete return trip of the balance wheel, i.e. two oscillations.

In an automatic watch, the movement is regulated by an escapement system which releases the energy stored in the mainspring in a controlled manner, thus allowing the balance wheel to maintain a stable frequency. A movement with a higher frequency will have better precision and will be less sensitive to external disturbances, such as shocks or temperature variations.

Conversion between alternations per hour and Hertz

To convert the vibrations per hour into Hertz, simply divide the number of vibrations by 7,200. For example, a frequency of 28,800 A/h corresponds to 4 Hz (28,800 / 7,200 = 4).

Impact of frequency on the quality and performance of automatic watches

The frequency has a decisive role in the precision and reliability of an automatic watch. The higher the frequency, the more precise and stable the movement. However, a higher frequency can also lead to higher energy consumption and thus reduce the autonomy of the mainspring.

Movement precision and stability

A high frequency movement offers better precision because each oscillation of the balance wheel is less sensitive to external disturbances. In other words, position variations, shocks or temperature changes will have less impact on time measurement. Also, an error of a few seconds per day will result in a smaller cumulative error over time.

Energy efficiency and autonomy

However, a higher frequency also means that the movement consumes more energy to maintain this rate. This can result in a reduction in the autonomy of the mainspring and require more frequent winding. It is therefore essential to find a balance between frequency and autonomy, especially for automatic watches intended for daily use.

Common frequency values ​​in automatic watches

Modern automatic watches generally offer movements with a frequency between 18,000 A/h (2.5 Hz) and 36,000 A/h (5 Hz). Here are some of the most common values:

• 18,000 A/hr (2.5Hz): Traditional frequency used in old mechanical watches and some pocket watches.
• 21,600 A/h (3Hz): Widespread intermediate value, offering a good compromise between precision and autonomy.
• 28,800 A/hr (4Hz): Standard frequency in many modern automatic watches, ensuring excellent accuracy and stability.
• 36,000 A/hr (5Hz): High performance frequency, allowing exceptional precision and better resistance to shocks, but which can reduce autonomy.

In short, frequency is a key element in the performance and quality of an automatic watch. It plays a crucial role in the precision of the movement and in the stability of the time displayed, while having an impact on the energy efficiency and autonomy of the watch.

Current frequency values ​​offer a wide range of choices for watch enthusiasts, allowing the right balance to be found between precision and autonomy according to individual needs and preferences.