How do Circuit Boards Work?
TechXpert verified by Ken Kontra
Circuit boards transfer electronic signals and power between different parts of a device. These are the brains behind your major home appliances, including your furnace, air conditioner, refrigerator, and more.
First Things First: What Does a Circuit Board Do?
Most circuit boards are known as Printed Circuit Boards (PCB): these are small pieces of board, normally made of a fiberglass material that replace bulky wiring and enhance the efficiency of your devices.
The primary function of a circuit board is to connect all the electronic components of a device in a compact space. It also ensures these components are safely insulated when they’re being connected to a power source.
Electricity travels through the circuit, which is a closed loop that allows for uninterrupted electrical flow to and from a power source through the conductor.
Types of Circuit Boards
Circuit boards are not a “one size fits all” appliance –– different appliances need different capacities, and the number of copper layers determines the complexity of the board. There are three main types of PCBs:
This is the most common type of PCB, composed of only one layer of conducting material (normally copper). It’s the easiest to design and produce and is primarily used in printers, calculators, radios, and other similarly small appliances.
This type of PCB has a layer of conducting material attached to both the top and bottom sides of the circuit board. It’s a little smaller than a single-layer PCB, making the circuit more compact. It’s commonly used in industrial controls, phones, amplifiers, and HVAC applications, like a furnace or air conditioner.
This type of PCB has more than two layers of conducting material and is insulated to avoid any heat damage to the circuit. It’s primarily used in more complex applications like satellite systems, medical equipment, and data storage equipment.
Each type of PCB serves a different purpose for electrical appliances to function properly. The larger systems and appliances in your home most likely use double-layered PCBs.
Components of the Circuit Board
Despite its small size, a circuit board has a number of parts working together so supply the power your appliances need to function correctly. Here are the four main components of a circuit board:
Energy source: Depending on your circuit, the energy can run through alternating current (AC) or direct current (DC).
Conductor: This part is usually a wire, often known as the track or trace, that carries energy.
Electrical load: This part consumes the energy, affecting the performance of the circuit in terms of voltage and current.
Controller switch: This switch controls the flow of power in the circuit.
While these are the four main parts, plenty of other important parts, like the battery, capacitor, and resistor have specific functions that are vital to the board’s operation.
These components are integrated to allow electricity to flow from a higher power voltage to a lower voltage, ensuring the appliances in your home are receiving the form and amount of power they need to function.
Potential Problems with Your PCB
Circuit boards are extremely efficient, but that doesn’t mean they’re perfect. One potential problem to watch for is a circuit that opens because of a damaged wire or loose connection. When this happens, your circuit won’t be able to conduct electricity, because even if there’s voltage present in an open circuit, it won’t have anywhere to flow.
Short circuits are other issues with PCBs: this happens when too much power moves through the circuit, which damages the board’s conductor or its energy source. Short circuits can be dangerous, and should be handled quickly to avoid any potential sparks or fires. If you don’t know your way around a circuit board, call in a professional technician to help.
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