How Gadgets Remember Time
Introduction to Timekeeping in Gadgets
In the world of electronic devices, maintaining accurate time is essential for various applications. From simple clocks to smartphones, electronic gadgets rely on precise timekeeping. This article explores three main methods used by different gadgets to remember time, focusing on the quality, accuracy, and dependence on external standards.Powerline Frequency for Timekeeping
Cheaper Gadgets: Powerline Frequency
One of the cheaper methods for electronic gadgets to remember time is by using the powerline frequency, typically 50 or 60 Hz, depending on the country. Gadgets like clocks and some oven timers utilize this method. These devices are powered by AC and use the powerline frequency as a time reference, making their accuracy highly dependent on the stability of the powerline frequency.Generally, these clocks provide very good timekeeping on utility power. However, they may not be as accurate on setups using solar power, inverters, or generators. The stability of the powerline frequency can be affected by fluctuations in the power supply, leading to less precise timekeeping.
Quartz Crystal Oscillators for Timing Reference
Most Electronic Equipment
Most advanced electronic gadgets, including computers, cellphones, GPS devices, and cable/satellite TV boxes, use a quartz crystal oscillator for a timing reference. The standard frequency for the quartz crystal used in time-of-day references is 32.768 kHz, which can be easily divided to give one pulse per second.The stability of the timekeeping depends on the quality of the components used and can vary with temperature. High-stability applications, such as those found in spacecraft or precision instruments, use a temperature-controlled box called a "crystal oven" to maintain a constant temperature, thereby ensuring frequency stability.
Self-Setting Clocks and External Time Standards
Self-Setting Clocks
Self-setting clocks, such as those found on computers and cellphones, rely on a connection to an external time standard. Time data is provided and updated regularly over cellular, satellite, or LAN connections from a central source, often an NTP (Network Time Protocol) server. The ultimate reference for these servers is typically an atomic clock, which can be either a Cesium or Rubidium clock.Some standalone self-setting clocks use a radio receiver to tune into broadcast radio time standard services like WWV (US Naval Observatory) or DCF77 (German national time and frequency radio station), both operated by governmental bodies like the National Institute of Standards and Technology (NIST) as public services.
The Internet and Network Time Protocol (NTP)
Standard Time Propagated on the Internet
Standard time is propagated across the internet using the Network Time Protocol (NTP). Most computers have a crystal oscillator and a local clock powered by a small battery, often called the BIOS battery. When the computer boots, the hardware clock's time is copied into the system time. This system time is maintained by the operating system and adjusted using small corrections obtained from NTP servers.GPS-Enabled Gadgets
Devices with GPS chips can obtain accurate time from GPS, which is synchronized with atomic clocks via satellite base stations. Similarly, cellphones can obtain accurate time via the cellular network, which is synchronized with atomic clocks via the internet or some other mechanism.In summary, the methods for gadgets to remember time are diverse, ranging from cheap and simple powerline frequency methods to more complex systems involving crystal oscillators and atomic clocks. The reliance on external standards, such as NTP servers and broadcast services, ensures that the timekeeping in these devices remains accurate and reliable.
Conclusion
The accuracy of timekeeping in electronic gadgets is crucial for a wide range of applications. Whether it's through the powerline frequency, quartz crystal oscillators, or external time standards, these methods ensure that gadgets can keep accurate time, providing reliable performance and functionality for users.