One of the key practical advantages of a pendulum clock is the fact that it doesn't rely on an external power source. Instead of using batteries or plugging in, falling weights or a spring mechanism provide energy to run the clock hands, chimes and any additional features, such as a moon dial or moving decorations. Users must wind pendulum clocks on a regular basis, using a key to coil the spring or draw up the weights. However, once wound, pendulum clocks will continue to run in the event of a power outage.
Pendulum clocks have been in use since the 17th century. According to Swarthmore College, they were among the most common types of clocks until the 1930s. This means that pendulum clocks represent many different era and movements in industrial and interior design. Pendulum clocks can enhance and lend authenticity to homes or rooms decorated in a traditional or period style. Some pendulum clocks are valuable antiques and others are works of art with handcrafted wooden cases, precision movements and precious metals used in their construction.
Despite their reliance on a technology that is hundreds of years old, pendulum clocks are highly accurate when maintained well and wound regularly. The swinging pendulum provides a resonant rhythm that measures time precisely and consistently. Much of the early popularity of pendulum clocks had to do with their accuracy compared to alternative time keeping devices. Quartz clocks that function normally are more accurate than pendulum clocks, but pendulum clocks are still more suitable for time keeping than other antique devices, such as hour glasses and candle-based clocks.
For hobbyists and do-it-yourself owners, pendulum clocks present the advantage of being serviceable. The components of a pendulum clock are usually visible and replaceable, when suitable parts can be found, allowing a clock owner to repair a pendulum clock as its components break down. This is very different from an electronic clock that features circuitry and a sealed case that prevents tampering and repair.