Back of a Hammond electric clock with the characteristic starting knob
Formerly
Hammond Clock Company (1928– 1935(1928– 1935)) Hammond Organ Company (1935– 1985)(1935– 1985)) Hammond Organ Australia (1986– 1989)(1986– 1989)) Hammond-Suzuki (1989– present)(1989– present))
As Stuyvesant Barry reports in his biography of Laurens Hammond,[1] Hammond himself acknowledged that his invention of the clock that was to bear his name was inspired by the success of Henry Warren's Telechron clocks. Upon discovering the Telechron technology, Hammond designed a motor that was synchronous, like Warren's, that is to say, it rotated at a speed that was tied to the frequency of the current supplied by the power grid. In this way, any clock operated by such a motor would run with great precision as long as the operators of the power grid kept the current's frequency constant. This had become possible since the introduction of the Warren master clock, an innovation of which Hammond took full advantage with his own invention.[2] Hammond's motor, however, differed from Warren's in a number of respects: above all, it ran more slowly and was not self-starting. (Warren had patented his self-starting technology.) The latter Hammond did not consider to be a disadvantage; he believed that people would be misled by their clocks if they restarted automatically after a power outage.[3] As Hammond's new clock motor was not self-starting, his clocks possessed a characteristic little knob on the back that one had to spin to start the motor.
The company
Due to its distinctive art deco skyscraper design, the "Gregory" is the most famous and popular clock among Hammond collectors.The Hammond clock model "Como"
The Hammond Clock Company was founded in 1928 to produce and market clocks that were equipped with Hammond's new motor. The Hammond clock factory manufactured more than 100 different clock models, some simple and cheap, others made from expensive materials such as marble and onyx.[4] Hammond employed well-paid toolmakers who created sophisticated tools to stamp out the various components of his clocks, which could then be assembled in a belt operation by unskilled laborers.[5] In addition, Hammond licensed his invention to other clock makers such as Waterbury, Sessions, and Ingraham.
In 1932, the economic troubles of the Great Depression threatened the clock-making industry; about 150 clock companies went out of business. To make matters worse, Hammond's licensees discovered that Hammond's patent on his motor was invalid, due to an earlier German invention of the same technology. In this situation, Hammond attempted to save his factory by starting the production of an electric bridge table.[6] This proved to be nothing but a fleeting success. Hammond did finally manage to save his company in 1931 with a $75,000.00 contract from the Postal Telegraph Company, for putting their company name on large electric wall clocks. These clocks were to replace old key-wind clocks in railroad stations. What further saved the company was his invention of the Hammond organ. His first model, the Model A Console organ was released in 1935, year in which his company was renamed "The Hammond Organ Company" to reflect the new emphasis. The production of clocks was discontinued entirely in 1941.
Notes
↑ See Stuyvesant Barry, Hammond as in Organ: The Laurens Hammond Story, chap. XII: "The Electric Clock." The work remains unpublished but is available on the web at The Hammond Organ Story.
↑ See the article on Telechron for an explanation of the Warren master clock.
↑ Warren tried to prevent this problem through his "indicating device," the red dot that would appear on the dial after a power failure. The "indicating device" is explained in the article on Telechron.
There is less literature on the Hammond clocks than on the Telechrons. Apart from some websites, such as the ones referred to in the notes, one may consult Spin to Start, the newsletter of the Synchronous Society, which was devoted to the collection of Hammond clocks. Only two issues have appeared, however: vol. 1, no. 1 (October 1996) and vol. 1, no. 2 (February 1998).
The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated sound by creating an electric current from rotating a metal tonewheel near an electromagnetic pickup, and then strengthening the signal with an amplifier to drive a speaker cabinet. The organ is commonly used with the Leslie speaker.
An electric motor is an electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft. An electric generator is mechanically identical to an electric motor, but operates in reverse, converting mechanical energy into electrical energy.
In electricity generation, a generator is a device that converts motion-based power or fuel-based power into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor therefore needs no electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type.
The electric power industry covers the generation, transmission, distribution and sale of electric power to the general public and industry. The commercial distribution of electric power started in 1882 when electricity was produced for electric lighting. In the 1880s and 1890s, growing economic and safety concerns lead to the regulation of the industry. What was once an expensive novelty limited to the most densely populated areas, reliable and economical electric power has become an essential aspect for normal operation of all elements of developed economies.
A synchronous electric motor is an AC electric motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integer number of AC cycles. Synchronous motors use electromagnets as the stator of the motor which create a magnetic field that rotates in time with the oscillations of the current. The rotor with permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field. A synchronous motor is termed doubly fed if it is supplied with independently excited multiphase AC electromagnets on both the rotor and stator.
The utility frequency, (power) line frequency or mains frequency is the nominal frequency of the oscillations of alternating current (AC) in a wide area synchronous grid transmitted from a power station to the end-user. In large parts of the world this is 50 Hz, although in the Americas and parts of Asia it is typically 60 Hz. Current usage by country or region is given in the list of mains electricity by country.
An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed into several types of instruments:
Laurens Hammond was an American engineer and inventor. His inventions include the Hammond organ, the Hammond clock, and the world's first polyphonic musical synthesizer, the Novachord.
Chord organ is a kind of home organ that has a single short keyboard and a set of chord buttons, enabling the musician to play a melody or lead with one hand and accompanying chords with the other, like the accordion with a set of chord buttons which was originated from a patent by Cyrill Demian in 1829, etc.
An electric clock is a clock that is powered by electricity, as opposed to a mechanical clock which is powered by a hanging weight or a mainspring. The term is often applied to the electrically powered mechanical clocks that were used before quartz clocks were introduced in the 1980s. The first experimental electric clocks were constructed around the 1840s, but they were not widely manufactured until mains electric power became available in the 1890s. In the 1930s, the synchronous electric clock replaced mechanical clocks as the most widely used type of clock.
Direct torque control (DTC) is one method used in variable-frequency drives to control the torque of three-phase AC electric motors. This involves calculating an estimate of the motor's magnetic flux and torque based on the measured voltage and current of the motor.
An induction generator or asynchronous generator is a type of alternating current (AC) electrical generator that uses the principles of induction motors to produce electric power. Induction generators operate by mechanically turning their rotors faster than synchronous speed. A regular AC induction motor usually can be used as a generator, without any internal modifications. Because they can recover energy with relatively simple controls, induction generators are useful in applications such as mini hydro power plants, wind turbines, or in reducing high-pressure gas streams to lower pressure.
An electric power system is a network of electrical components deployed to supply, transfer, and use electric power. An example of a power system is the electrical grid that provides power to homes and industries within an extended area. The electrical grid can be broadly divided into the generators that supply the power, the transmission system that carries the power from the generating centers to the load centers, and the distribution system that feeds the power to nearby homes and industries.
Telechron is the name of a U.S. company that manufactured electric clocks between 1912 and 1992. "Telechron" is derived from the Greek words tele, meaning "far off," and chronos, "time," thus referring to the transmission of time over long distances. Founded by Henry Ellis Warren, Telechron introduced the synchronous electric clock, which keeps time by the oscillations of the alternating current electricity that powers it from the electric power grid. Telechron had its heyday between 1925 and 1955, when it sold millions of electric clocks to American consumers.
Henry Ellis Warren was an American inventor credited with invention of the first synchronous electric clock which kept time from the oscillations of the power grid in 1918 as well as with 134 other inventions. Warren founded Warren Telechron Company in 1912 which later was acquired by General Electric in 1943. Warren was noted as the "father of electric time". Telechron went out of business in 1992. Just between 1916 and 1926 the company sold 20 million clocks. The clocks remained popular into the 1950s. In 1940 he also invented the "singing clock" which instead of a pendulum had a vibrating metal string.
George Lewis Graff was an American industrial designer active in the 1920s and 1930s.
Arthur William Haydon was an American inventor and industrialist known for his work in the field of microminiature electrical timing and governing devices for industrial and military use, some of which were used in early computing devices.
Synchronverters or virtual synchronous generators are inverters which mimic synchronous generators (SG) to provide "synthetic inertia" for ancillary services in electric power systems. Inertia is a property of standard synchronous generators associated with the rotating physical mass of the system spinning at a frequency proportional to the electricity being generated. Inertia has implications towards grid stability as work is required to alter the kinetic energy of the spinning physical mass and therefore opposes changes in grid frequency. Inverter-based generation inherently lacks this property as the waveform is being created artificially via power electronics.
Sidney Howe Short was an electrical engineer, inventor, physicist, professor and businessman. He is known for the development of electric motors and electric railway equipment. His inventions were so successful that even his competitors dubbed him "The Trolley King". He also developed telephone equipment much like that of Alexander Graham Bell. As a businessman he was president, key engineer, or advisor of different companies related to electrical equipment. It is claimed that he had nearly as many electrical innovations as Thomas Edison.
This page is based on this Wikipedia article Text is available under the CC BY-SA 4.0 license; additional terms may apply. Images, videos and audio are available under their respective licenses.
