16 November 1904: John Ambrose Fleming patents the oscillation valve

On this day in 1914, John Ambrose Fleming patented his oscillation valve – a component which formed the basis of the electronics industry for half a century.

Perhaps the only contact many of us have with the sort of valves you get in electronics these days is if we have an ageing cathode-ray tube TV, or if we know a particularly boring audiophile who is prone to drone on at length about how his organically grown amp produces a much richer, more vibrant sound than your puny CDs or that new fangled streaming "music" that all the kids are listening to these days.

But valves (which our Americanly-challenged friends call vacuum tubes) were the backbone of the electronics industry for 50 years or so, until they were superseded by solid-state transistors.

And it's all thanks to the efforts of John Ambrose Fleming, the first professor of electrical engineering at London's University College, who also worked for both Marconi and Edison. He invented the oscillation valve, which he patented today in 1904. It was, without doubt, one of the most important developments in the history of electronics.

Fleming's valve was the first practical application of the “Edison effect” – the phenomenon of “thermionic emission” whereby electrons flow from a heated element to a cool one – which Edison observed while creating his electrical light bulbs. Indeed, in many ways, Fleming's “thermionic” valve is little more than a modified light bulb.

By heating an electrode inside a glass bulb containing a vacuum, it is possible to “rectify” an electrical current and radio waves, and amplify them. And the later addition of a grid through which the electrons had to pass meant the current could be regulated.

The valve's invention led to the introduction of radio around the world, the discovery of radar, and eventually to the supercomputers and artificial intelligence of today.

Recommended

Cryptocurrency roundup: authorities tighten the screw
Bitcoin & crypto

Cryptocurrency roundup: authorities tighten the screw

Saloni Sardana looks at the cryptocurrency stories that caught our eye this week.
21 Jan 2022
Stockmarket crash: is the “superbubble” heading for a “superbust”?
Stockmarkets

Stockmarket crash: is the “superbubble” heading for a “superbust”?

America's Nasdaq stock index is down by more than 10% after soaring to all-time highs in a "superbubble". Are we about to see a "superbust" stockmarke…
21 Jan 2022
Inflation: now we really have something to worry about
Inflation

Inflation: now we really have something to worry about

We’ve been worrying about a sharp rise in inflation for years, says Merryn Somerset Webb – now, we finally have something to worry about.
21 Jan 2022
Share tips of the week – 21 January
Share tips

Share tips of the week – 21 January

MoneyWeek’s comprehensive guide to the best of this week’s share tips from the rest of the UK's financial pages.
21 Jan 2022

Most Popular

Ask for a pay rise – everyone else is
Inflation

Ask for a pay rise – everyone else is

As inflation bites and the labour market remains tight, many of the nation's employees are asking for a pay rise. Merryn Somerset Webb explains why yo…
17 Jan 2022
US inflation is at its highest since 1982. Why aren’t markets panicking?
Inflation

US inflation is at its highest since 1982. Why aren’t markets panicking?

US inflation is at 7% – the last time it was this high interest rates were at 14%. But instead of panicking, markets just shrugged. John Stepek explai…
13 Jan 2022
Interest rates might rise faster than expected – what does that mean for your money?
Global Economy

Interest rates might rise faster than expected – what does that mean for your money?

The idea that the US Federal Reserve could raise interest rates much earlier than anticipated has upset the markets. John Stepek explains why, and wha…
6 Jan 2022