Pendulum clocks have accentuated the decor of homes for centuries. Even today, the popularity of these clocks has not diminished and they continuously remain in demand. For over 270 years pendulum clock had remained the world standard for accurate time keeping. After the invention of quartz clock in 1927, they are mostly kept for their antique and decorative value. If you have a pendulum clock at home or planning to buy one, you may wish to know how pendulum clocks work. Let us how its mechanism and enchanting detail which makes it highly popular decor product.

A pendulum clock uses a pendulum and a swinging weight as a time keeping element. All mechanical pendulum clocks generally have these five parts.
1. There is a power source which can either be a weight on a cord, a chain turning a pulley, a sprocket or a mainspring. 

2. A gear train, stepping up the speed of the power for pendulum to use it.

3. An escapement giving the pendulum precisely timed impulses so as to keep it swinging. It even releases the gear train wheels so that it can move forward a fixed amount at each swing.   

4. A dial or an indicator that records how often the escapement has rotated signifying how much time has passed.

5. The pendulum, a weight on a rod. 

But there are some more sophisticated pendulum clocks that include some additional features.
      
1. Striking train- It strikes a chime on every hour. The number of strikes is equal to the number of hours.

2. Calendar dials- It shows the day, date and even months of the year.    
        
3. Moon phase dial- This pendulum clock shows the phase of the moon generally with a painted picture of the moon positioned on a rotating disk.
 
Many people have wondered how a pendulum in a mechanical clock functions. Since it does not have any electricity, from where does it take its energy?  Weights and springs are the two mechanisms that keep the pendulum swinging.      
                                                                                                                                                                                         
Weight mechanism- Weights or chains of the clock hang from the main mechanism. In a pendulum clock, as the pulley swings, the weight then slowly lowers and transfers their potential energy to the pendulum.  This enables the pendulum to keep it swinging. The weight constantly keeps pulling downwards on the gear thus trying to turn it.

Pendulum clock swings back and forth in a precise time interval. This depends on its length but resists swinging at other rates. To avoid inaccuracy, pendulum clock must be stationary to operate. This is due to the fact that any type of acceleration or motion might affect the motion of the pendulum.