How Transistors Work

Transistor Radios and the Electronics Revolution

Transistors work primarily as switches and amplifiers. Given those functions, it's no surprise that sound-related devices were the first commercial products to use transistors. In 1952, transistorized hearing aids hit the market. These were niche products, though, compared to transistor radios that emerged in 1954. Radios exposed manufacturers and consumers alike to the revolutionizing potential of transistors.

The function of transistors in radios is straightforward. Sounds are recorded through a microphone and turned into electrical signals. Those signals travel through a circuit, and the transistor amplifies the signal, which is subsequently much louder when it reaches a speaker.


Convincing manufacturers that this basic concept would work on mass-produced products, however, wasn't such a simple task. In 1954, transistors were proven but novel electronic components. Device manufacturers had been using vacuum tubes profitably for many years, so they were understandably leery about switching to transistors.

But Pat Haggerty, vice president at a company called Texas Instruments, was convinced that transistors were going to revolutionize the electronics industry. Texas Instruments used Bell Labs' breakthroughs in germanium transistors to develop a small, pocket-sized transistor radio, with the help of a small Indiana company named IDEA. Together, the two companies created a radio called the Regency TR-1, which was announced on Oct. 18, 1954.

From start to finish, the race to create the TR-1 required innovative new parts that would fit inside a pocket-sized case, which would be small enough to really capture the world's attention. The speaker, capacitors, and other components were created just for this project. The transistors, though, were what really made the project possible.

Texas Instruments devised processes for mass-producing transistors for their radios, and in the process, proved that transistors and their subsequent products could be affordable, more portable and more effective than vacuum tubes. Within a year, other companies, such as Emerson, General Electric and Raytheon, all began selling transistor-based products. The modern electronics boom had begun.