Bill examines the first transistor ever built. He explains how it works, and its impact on our world today. And, also, he even tests it out!
Transcript This [suitcase] contains a truly amazing engineered object, one that has changed our world dramatically .... I suppose I should wait ... but what harm can come of this.
This is the first transistor ever built! It gave birth to all the computers, cell phones, and other gadgets that we use. One of its inventors - John Bardeen - was a professor here at the University of Illinois. This two-time Nobel Laureate donated it to our fine Spurlock Museum. They've been kind enough to bring it over for me to show to you.
Oh look! They have with it a vintage electronics magazine with the inventors on the cover. This man [holding up magazine] Walter Brattain built in 1947 the actual transistor we're looking at. This is amazing to see this iconic device!
The heart of this transistor is this kind of metallic looking chunk here. It a piece of germanium - it's a semi-conductor. You've likely heard of insulators, which don't conduct electricity, and metals, which do conduct.
A semiconductor can be made to "switch" from an insulator to a conductor. That "switching" allows it to amplify a signal.
For example, when Bardeen and Brattain tested this they actually amplified their voices. On this side of the transistor they hooked up a microphone with a small battery to this gold strip and to the copper base below the semiconductor; and on this side they attached to this gold strip and to the copper plate a speaker, a large battery and also an oscilloscope so they could see the signal. The tiny signal from that small battery then amplified the transistor powered by this huge battery over here. That's exactly what is done today, for example, in a cell phone: A weak signal from the tower is amplified until you can here.
This doesn't of course fit into a cell phone, but because this is just a chunk of germanium it has no moving parts which means it it can be miniaturized, takes no time to warm up, and is very reliable. This makes possible our electronic world: A computer today has fifty million transistors.