Today's most common timepiece is the quartz clock, the quartz crystal vibrates at a MHz rate, operated via a circuit, driven by a battery, or rather a mono-cell, since a real battery consists of a number of cells, i.e. 6 x 2-Volt cells makes up a 12 Volt car battery.

Prior to the mass produced quartz clock we had the battery clock, to distinguish this timepiece from electrically (mains) driven or spring- or weight driven clocks. With the development of the battery clock the power source, weight, spring or mains electricity was replaced by a battery. The rest of the clock movement was still mechanical, namely the transmission via a set of wheels to the oscillator, usually a spring balance, or fly wheel as it is sometimes erroneously called.

Oscillators determine the timekeeping, and are devices which must have a steady frequency. A long pendulum in a "Grandfather Clock", a shorter one in a "Wall Regulator" or a very short pendulum in a mantel clock are excellent to reasonable oscillators, but these clocks are not portable. Of course they can be moved and transported with the appropriate precautions. (refer to my previous article, May 2008) Portable timekeeping started about 500 years ago when Peter Henlein produced the first pocket watch in his smithy in Nürnberg/Germany.

Back to the electro mechanical battery clocks which came onto the market about 50 years ago. In most of these clocks the battery powered a solenoid to activate a lever which in turn tensioned a weak spring, this giving power to the rest of the clock (wheel train and spring balance). Actually in the very first models, a small weight on a ratchet was kicked up and gravity gave the required power. Soon a small helical- or coil spring replaced the weight. As the battery was used only for a few milliseconds every 3 minutes, it's life was about three years. The timekeeping was still done mechanically via the spring balance.

Once transistors were used to regulate current we talked of electronic clocks. But the basic flow of power was reversed, not any longer from mainspring or weight via wheel train to balance, but from the balance (oscillator) down to the wheels which carry the hands. That is the same with the modern quartz clock, the quartz crystal with it's high frequency governs the timekeeping.

There was much less wear already in electro mechanical battery clocks, but with the electronic clock, and more so the quartz clock this was reduced to virtually nothing. Most malfunctions could be ascribed to moisture, dust or tiny insects in the fine wheels. If you want to send illustrations via e-mail, please note that I cannot accept Megabyte files straight from your camera/cell phone. 50 KB per image with a total of 300 KB is a good e-mail standard for me. Thomas Niemeyer July, 2009