20 January,2015 08:02 AM IST | | A Correspondent
On the 185th birth anniversary of Welsh-American scientist and musician David Edward Hughes, inventor of the first carbon microphone, we take a look at the man's contribution of the world of sound through this creation...
David Edward Hughes, carbon microphone, carbon microphone inventor, Thomas Edison, great inventions
David Edward Hughes' carbon microphone, which was independently developed by him in England and Emile Berliner and Thomas Edison in the US, was the first microphone that enabled proper voice telephony. The 'loose contant' carbon microphone was then referred to as a transmitter. Edison was awarded the patent for device after a long legal battle in mid-1877. Hughes had however demonstrated his working device in the presence of several witnesses some years earlier and is thus credited as the microphone's inventor by several historians.
David Edward Hughes.Pic/YouTube
The carbon microphone contains loosely packed carbon granules. The varying pressure exerted on the granules by the diaphragm from the acoustic waves caused the resistance of the carbon to vary proportionally. This allowed a relatively accurate electrical reproduction of the sound signal. The credit of coining the term 'microphone' also goes to David Edward Hughes, who demonstrated the device his apparatus to the Royal Society by magnifying the sound of insects scratching through a sound box and decided not to patent his innovation; instead giving it as a gift to the world, a view that was contrary to Edison's.
(Above and below) A couple of diagrams illustrating David Edward Hughes' carbon microphone
In 1886, Thomas Edison refined the carbon microphone into his carbon-button transmitter and it was employed at the first ever radio broadcast, a performance at the New York Metropolitan Opera House in 1910.
Did you know?
>> David Edward Hughes designed the first printing telegraph system in 1855. In less than two years a number of small telegraph companies, including Western Union in early stages of development, united to form one large corporation - Western Union Telegraph Co. to carry on the business of telegraphy on the Hughes system. In Europe, the Hughes Telegraph System became an international standard.
>> Hughes also stumbled upon what would later be known as the first working radio communication system in 1879, when he discovered sparks would generate a radio signal that could be detected by listening to a telephone receiver using his new microphone design as a detector. Using trail-and-error experiments, he developed his spark-gap transmitter and receiver into a working communication system. Eventually he could demonstrate the ability to send and receive Morse code signals out to a range limited to 500 yards (460 m). Hughes demonstrated his invention in the presence of prominent attendees, which included, Sir William Crookes, Sir William Henry Preece, William Grylls Adams, and James Dewar.
>> David Edward Hughes invented the induction balance, which was later used in metal detectors.
