Krafts Clock Repair

There are actually four different kinds of electric clocks.

Electromechanical clocks. There are two types of these clocks. The first uses mechanics to rewind the mainspring, such as a motor, or even an electromagnet.

The second uses mechanics to run either a pendulum or an oscillator.
Electromagnetic clocks are those that use electromagnetic pulses or impulses to run the pendulum or oscillator.

Synchronous clocks. These are the clocks that you plug in to the wall outlet that use the 50 or 60 HZ line frequency from the AC line current as a timing source, and they drive gears with something called a synchronous motor. Henry Warren of Ashland, MA was an MIT alumnus (B.Sc. Electrical Engineering, 1894) and was an inventor. One of his excellent inventions was the self-starting electrical synchronous motor, which he used to create reliable electrical clocks. In addition to being the inventor of the electrical clock he was a successful entrepreneur who founded a company, Telechron, to manufacture electrical clocks.

Electric were developed in the early days of clock making, around 1814.

This is when Sir Frances Ronalds invented the earliest type of electric clock, the electrostatic clock. His clock was powered by a dry electro pile, or battery that was made of alternating layers of paper, with one side having nickel coated on it and the other side having manganese oxide. These were piled on top of each other and produced a small voltage. However, this clock did not keep good time at all, but it was the forerunner of another type of clock.

Again, around the same year of 1814, Giuseppe Zamboni, also developed an electrostatic clock, but his used an oscillating orb. It was considered the most elegant of the time, and his clock ran for 50 years on one battery!

Another clockmaker, named Matthias Hipp, born in Germany, is credited with establishing the production series, mass marketable electric clock. In Switzerland ,Hipp opened a workshop where he developed an electric clock. It was called the Hipp-Toggle and was presented in Berlin at an exhibition in 1843. The clock had a device attached to a pendulum or balance wheel that electromechanically allowed and occasional impulse to the pendulum or wheel as its amplitude of swing drops below a certain level, and it was so efficient that it was subsequently used in electric clocks for over a hundred years.

In around 1931, the electric companies established the standard 60 HZ line frequency. Since this was kept as a standard, it was now possible to make a plug in electric clock the was accurate in time keeping. The used a synchronous motor the used the 60 HZ frequency to keep running at a determined rpm. When this motor’s shaft was connected to gears, it was able to run the hands on a clock and it kept very good time. These clocks also had Chimes that struck on the hour and half hour. Telechron, the earliest and best known company, made special rotors that fit into a steel laminated frame that had the field coil on one leg of the frame. These motors were compact, but most of all the ran quietly, and could be used in the bedroom.

There are many other types of motors that ran clocks, but they all use the 60 HZ line frequency for time keeping.

Battery clocks use permanent magnet motors to run them. Most of these only used the motor to wind up a mainspring which ran the clock.

Later, quartz clocks were developed, with the first coming about in 1921. The use a quartz crystal that oscillates at a determined rate or frequency, usually 32,768 Hz and this is the basis of their time keeping accuracy; the quartz and associated electronic circuitry is very accurate.

This is what is used mostly today in modern clocks. Batteries used in these clocks will most of the time run for a full year with great accuracy.

Another type of quartz clock uses a radio receiver inside the clock that actually is tuned to WWV, a radio station that transmits time signals on frequencies of 2.5, 5,10, 15, and 20 megahertz, and are based on the atomic clock at the National Bureau of Standards. It is possible to have a clock in your home with atomic clock accuracy with one of these. 

Technology has changed the accuracy of clocks, but their use is still the same, to tell the time by which we all govern our lives. Time and its measurement is called the science of Horology, and is a fascinating study, one which is always being improved and innovated on. Becoming a part of it means to join a long line of distinguished scientists and inventors who dedicated their lives to the study of time measurement. It is a dying art, but with more and more interest, it is being revived and will continue well into the coming years.