About the ‘father’ of electronics, Professor Sir John Ambrose Fleming

I give it a privilege to be built on behalf of the institution of electrical engineers and I believe I may I may add that I think I am one of the oldest of their members having an John Ambrose Fleming was a true pioneer of electronics and radio telegraphy. His research, which spanned over 50 years, led to one of the most important inventions of the 20th century, the thermionic valve.

 Back in 1865, the Scottish scientist James Clark Maxwell predicted that it should be possible to make an alternating current send electromagnetic waves through the air. 22 years later, Hinrich Herz proved Maxwell right. He used a high alternating voltage to produce sparks. Each time a spark occurred, a pulse of current passed through the circuit and electromagnetic waves were radiated.

 However, some scientists were developing improved types of detection systems. Ambrose Fleming, a professor of electrical engineering at University College London, had worked directly under Maxwell whilst at Cambridge University. His research into electromagnetic radiation led him to take up where Hertz had left off. He began experimenting with the most sensitive of the early detectors at that time, the [Music] Cohira.

 In 1896, Gugglmo Maronei arrived in Britain with his magic box, a homemade Cohira receiver. He was keen to bring it to the attention of the general public and of course his fellow scientists and began giving demonstrations around the country most notably on the aisle of white sending Morse code signals 12 mi to the mainland to Bournemouth and pool.

 Nevertheless, these demonstrations although largely successful over medium distances were not what he had in mind. His real goal and aspiration was crossing the Atlantic Ocean. Fleming was so impressed with Marone’s experiments that it wasn’t long before he was appointed to the Maronei company as a scientific adviser.

 This meant that Fleming would apply both his knowledge and experience to building the powerful transmitters required to span the Atlantic. And in 1901, Maroneian Fleming constructed the first long-distance wireless station in the world at Paulhoo in Cornwall. Fleming was given the task of designing a power plant capable of generating 20,000 [Music] volts.

 And in 1901, the first of the huge aerials were erected in preparation for the test transmissions. Huge sparks thundered around the Cornish coes as the dots and dashes were tapped out on the transmitter. After several anxious weeks, Fleming achieved a successful transmission to Maronei, who was waiting at St. John’s Newfoundland.

 1,800 m away. But for all their success, Coheras had one fundamental problem. They were unreliable in operation. During the past 55 years, it has been my privilege to be closely associated with the introduction into Great Britain of three great inventions. The telephone, the electric incandescent lamp, and wireless telegraph.

Having been scientific adviser to the Edison company for many years, Fleming was able to use this experience to solve the problem of the coher. In 1904, he successfully created a twoelode valve out of an Edison lamp. An important feature of this valve was that it passed a current in one direction only.

 When inserted together with a galvvinometer into a tuned electrical circuit, it could be used as a very sensitive rectifying detector of highfrequency wireless currents, radio waves. This device became known as the thermionic valve and it created a new manufacturing industry giving employment to thousands of people.

 Fleming’s valves were the first electronic components. They were the forerunners of the modern triode valve which resulted in a number of modern electronic developments such as semiconductor diodes and transistors for controlling and amplifying current. These were smaller, cheaper and more reliable to produce and opened the way to mass consumer electronics.

 It also led to research into the new field of nanotechnology which could be used to produce micro triode devices that are invisible to the naked eye. But today, the Valve is far from dead. They can still be found in expensive, highquality power amplifiers and microphones used in professional recording studios around the world.

 Fleming was recognized for his great talent when in 1910 he was awarded the Hughes Medal in recognition of his original discovery. At the age of 77, he retired from his chair at UCL and two years later in 1929 was given a nighthood for his lifelong achievements to science and industry. And although now retired, he never really gave up his interest in electronics, especially now that the medium of television had arrived.

 At the grand age of 95, Sir John Ambrose Fleming died in Sidmouth, Devon. To many students of physics, he will be remembered for his left and right hand rules which indicated the directions of the field, current and force in electrical machines. To the world of science, he was a great pioneer of electronics and radio telegraphy.

 He paved the way for a wireless revolution that has made a dramatic impact on society, changing the lives of millions of people around the world.