Electronic circuits are the new building blocks of the modern age. They facilitate almost all of the electronic devices that help us as a species maintain a high degree of productivity, efficiency, and entertainment. Few people, however, have any idea what’s in a circuit board. If you’ve always wondered what exactly makes your devices tick, read on.
- Resistors
Resistors are components that resist the flow of electricity. There are many different kinds, with a key difference between them being the power they can handle before they blow, as well as how well they can resist current. They are extremely important in protecting the circuit from being overloaded by too much electrical activity and are best thought of as a dam that can open and close depending on how much water needs to be let through. Many electronic devices only need a little bit of current, so the metaphoric dam lets a trickle of water through so it doesn’t destroy everything downstream.
- Capacitors
Capacitors store electric charge on a temporary basis. Their capacity is measured in a unit called a microfarad, and they are often made from ceramic disks. They release electricity as an alternating current, but they can receive direct current, making them a useful tool in adapting circuits to DC supplies.
- Diodes
Diodes are components that can be highly varied, but they almost universally allow electric current to be monodirectional only. That’s because they use anodes and cathodes that need to be charged with positive and negative charges respectively. If the voltage is reversed (and the cathode receives the positive charge and vice versa), they cannot allow charge to flow. The notable exception is the Zener diode, named after Clarence Zener, which takes advantage of electron quantum tunnelling to allow current to flow backward at a certain voltage. This is very useful in circuits that need a low stable voltage. For a device that involves quantum physics to function, they only cost fractions of a dollar from a Zener diode supplier.
- Inductors
Inductors consist of a coil of wire around a core, which is essentially an electromagnet. They form a magnetic field, the closer to the core, the better. This gives them several uses, including their application in traffic lights as they can be used in sensors to detect the amount of traffic and change the signal accordingly.
- Transistors
Transistors have three terminals, with electric flow controlled by the base terminal. Transistors are widely used to amplify or to switch electrical signals. They were highly useful in transistor radios, which take advantage of the fact that the controlled output power can be higher than the controlled input power. Most are made from pure silicon, and they are part of the reason why electronics and technology are so associated with silicon.
- Microcontrollers
Microcontrollers are small computers that are often bolted onto a circuit to control many different devices. They contain at least one CPU and have memory that’s often included on a computer chip. They are different to the processors in personal computers and other applications as they normally have a very specific purpose.
