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Let's take Nicolai Tesla as example. He was mainly concerned with electromagnetic energy stored in coils. The famous Tesla coil is amazingly powerful even by today's standards. As the Internet shows, people still build them. Tesla was an advocate of AC electrical power and wisely so. Edison wouldn't have it and stuck to DC all his life while Tesla built the world's first AC power plant. But he also believed that he could surround the earth with an electromagnetically resonant wave and feed all the homes in the country directly from that. He never succeeded, claiming his experiments were sabotaged. He did very dangerous experiments with artificial lightning. He claimed energy could be captured freely by lifting a plate high up in the air to collect solar electrical energy and store that in a capacitor. Free energy for all! During WWI, Tesla even built a tower on the US East-Coast and claimed that he could destroy enemy armies thousands of miles away using beamed electromagnetic energy. The authorities tore down the mythical tower before it became operational. Neighbors were too scared. Tesla had become so excited by all the new developments and possibilities of his time that his imagination went wild. Type Tesla into Google, then add Tower and after reading for an hour or so, you will see what I mean.

During that time, Thomas Alva Edison melted a carbon filament wire into a glass bulb, applied a vacuum pump and created an electric light which lasted longer than the instantaneous flash of a filament wire in free air. But after a while the glass darkened on the inside. And Edison also noted that when a filament finally burnt, the break always occurred at the negative side of the wire. Possibly in an attempt to find a way of preventing the glass from blackening, he made a bulb with an extra inner metal plate connected to a lead-out wire. He had already developed a moving coil meter for measuring currents and now connected such a meter to the lead-out wire, possibly to see if he could catch an unknown current and divert it from the glass.


Connecting the other side of the meter to the negative gave nothing but he did find a current when connecting the meter to the positive end. Although the discovery of a current through a vacuum looks like hot news to us now, in 1884 Edison stopped there perhaps because the extra plate did not prevent the glass from blackening. He did file a patent not for the bulb with the plate but for the moving coil meter yet the first electronic device ever appears in the drawing of the patent as the object being measured. One or two of these lamps traveled across the Atlantic and ended up on the workbench of one John Ambrose Fleming. Fleming was intrigued and his experiments confirmed Edison's findings. But we are still two years removed from the discovery of the electron. Fleming couldn't proceed and in 1896 finally locked the lamps away in a cupboard.

Five years later Marconi meant to improve upon his first stunt but now to cross the Atlantic with his wireless telegraph signals. The detection of the weak signal at the reception side was a problem though. Marconi used a coherer, a device in which iron powder moved by magnetic fields. It was then that Fleming remembered Edison's plate lamps which were subsequently applied as diodes and successfully so. Now it is 1904. Why did Lee de Forest add a third electrode to the diode? He hadn't seen the light so to speak. He didn't intend to do something revolutionary; he just meant to be different. De Forest was building telegraphy detectors and he couldn't use the two-element device Fleming had brought to Marconi (and also because a US competitor of De Forest was using something similar). So he added a third electrode to escape patent infringement. That explains how this third electrode (a plate by the way, not a grid) ended up in the wrong place on the other side of the filament instead of between filament and anode. He spoke of a 'gaseous medium' and 'ions around the filament', both of which are the last things you would want in a radio valve! He inserted electro magnets in his circuit expecting to modulate the location of his third electrode. Conclusion? He had no clue what had fallen into his hands. See the December 1906 Audion patent (No. 841,387) which he filed.


A second patent followed in June 1907, this time actually for a sort of grid between filament and plate. Unclear is why he did so. Presumably this appeared to work better in his detector circuits. He never used his Audion as an amplification device until about 1912 but even then he himself hardly believed in it since he sold his entire non-wireless patents to Western Electric for not too much money. Western Electric did need amplification devices for their long distance telephone line, and although De Forest's Audion was a very weak performer in that area, in 1914 one Edward Armstrong at WE realized the potential value. It took him another two years to turn it into a useable product. If Western Electric hadn't been there and then, we would not be together here now at this Triode Festival.

This whole development paved the way for something as sublime as radio. It had been a discouragingly slow process though, from 1884 through the mile stones of 1896, 1901, 1906, 1907, 1912 and 1914. It eventually also paved the way for audio and hifi. But maybe more importantly, this rather sorry story also marks the beginning of electronics.


It is not easy to make a clear distinction on when something electrical becomes electronic. For instance, it is not strictly necessary to have an active device in a circuit to characterize that circuit as electronic. Everyone will agree that a simple radio receiver consisting of just a coil, a capacitor, a diode and headphones, all of them passive components, is electronics. But how about a transformer followed by a diode bridge and an electrolytic capacitor? When it feeds valves and (god forbid) transistors, it would be electronics, right? But when it feeds a DC motor, it can't be more than electricity. Or can it? I'll leave it to you to try and define what electronics is and isn't. We'll simply agree on one thing today: if it happily glows in the dark, it is electronics!

Peter van Willenswaard