Practical Uses for Transistors


Transistors are like mini-brain cells. The invention of silicon transistors revolutionized modern electronics and today, they are found in multiple devices.

How Do Transistors Work?

Transistors can have two functions. They either operate as a switch or as an amplifier. When a transistor works as a switch, it conducts current when the voltage reaches the base. Otherwise, the switch is turned off. If used as an amplifier, the current flows in one end of the transistor and is boosted into a much bigger current.

As you might expect, there are plenty of useful applications for transistors in electrical equipment and systems.

Computer Chips

Modern transistors are commonly used in computer memory chips, usually as ‘switches’. They can be found on solid-state drives used for digital cameras, games, and smartphones. Transistors are also used in microprocessors, where the on/off correspond to binary 1/0. They are found in laptops and PCs.


Transistors are a vital component of telecommunications systems, where switching circuits are an important part of the technology.

Hearing Aids

One of the first modern uses for transistors was in hearing aids. A hearing aid has a small microphone that detects ambient sound around the person. These are turned into a current, which is fed through the transistor and into a loudspeaker, which amplifies the sound. These devices are quite literally life-changing for deaf people.

Pocket Radios

Another early use for transistors was in the development of pocket radios. Because they were very small, transistors were used to replace much larger vacuum tubes or valves in oscillator circuits in radio equipment. This enabled much smaller radios to be manufactured.

The Future of Transistors

Transistors are incredibly efficient at amplifying and switching current on and off. As technology has advanced, silicon transistors have become increasingly small, but the downside to this is that the barrier between the on and off is thin and the transistor never truly switches the current ‘off’.

One of the reasons why laptops and PCs tend to get very hot is because the transistors in the chips are constantly leaking power, which manifests as heat. This is why modern computers contain cooling fans, although, in the case of laptops, they are not always that effective. This is also the case in gadgets created by amateur electronics enthusiasts, who use a transistor search engine to find the parts they need.

There will come a time when silicon transistors are superseded by something better. What that will be remains to be seen, but materials scientists are working hard to come up with a suitable successor to silicone transistor chips.

Magnets have properties that could be harnessed to switch an electrical current on and off. These properties were explored by Peter Grünberg, who later won a Nobel Prize for his work. However, it may be some time before magnets replace silicon transistors in smartphones and laptops.

Mott insulators are something else that could one day replace silicon, but scientists don’t yet fully understand how exactly mott insulators work, and the only working mott prototype so far wasn’t practical for a small electronic device like a smartphone.

What does the future look like for transistors? Watch this space.


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