A power supply is an electronic device that delivers energy to other components within a system. The power supply acts as the bridge between the power source and the components. That means that the components cannot function unless they get energy from the power supply. But before energy is delivered to electronic components, it must first be processed to convert it into a form that can be used by the components.
The power supply gets energy in AC (Alternating Current) form and changes it into DC (Direct Current) form. The power supply must be connected to a reliable source of energy or else it will have nothing to deliver to the components that depend on it. In case a power supply has broken down, it must be repaired or replaced immediately because the entire system depends on it.
Power supplies come with input and output terminals. The output terminals are usually connected to the components that use the energy that has already been transformed. On the other hand, the input terminals are reserved for tapping into the original source of energy. Though power supplies that get their energy from electricity are the most popular, there are others that source energy from fuel, solar and batteries.
Functional Classification of Power Supplies
Power supplies are classified by how they function.
- Regulated power supply: This one never increases or reduces its output but delivers a fixed amount of voltage even when input voltage changes.
- Unregulated power supply: This device reduces and increases its voltage input according to the variance in voltage needs of the components on the receiving end.
- Adjustable power supplies: This type of power supply comes fitted with knobs for increasing and reducing output voltage. The adjustment knobs are usually placed on the front panel of the power supply.
- Adjustable regulated power supply: It is a power supply that has adjustment buttons and is regulated not to exceed a certain amount of voltage.
- Isolated power supply: This is a unit whose output never relies on its input. Such power supplies are very rare.
Mechanical Classifications of Power Supplies
Power supplies are also classified based on their packaging.
- A bench power supply: is basically a desktop device that functions independently. This type of power supply is usually reserved for testing circuits while they are still being constructed.
- Open frame power supply: In this kind of power supply, only a small fraction of the device is covered with a casing. In some cases, a base for fixing the power supply on other equipment is created.
- Rack mount power supply: This power supplies are usually found in most electronics such as radios and TVs.
Types of Power Supplies
- DC power supply: Since this type of power supply gets its energy from a DC source, only one voltage polarity is delivered as input. This means that if its delivering negative voltage, that’s all you will get and vice versa. On the other hand, if the power supply delivers positive polarity, negative polarity will not be available.
- AC to DC power supply: In this type of power supply, energy is obtained from electricity in the form of AC. In such a case, a transformer is fixed in the middle to transform AC voltage to DC voltage. Besides that, the transformer reduces or increases the input voltage of the power supply. Transformers that boost voltage are specifically used in the national grid. Transformers that are usually found in most electronics are for reducing their voltage.
- AC power supply: This power supply uses electric energy. But since energy from the national grid comes with high voltage, the power supply must process it and bring it down to a standard voltage that’s safe for components. If such high voltage is not reduced, it can easily blow up your components due to excess energy levels.
- Switched-mode power supply: This device delivers DC voltage by first rectifying the AC energy. An inductor or a transformer is used to filter the current. This energy is then switched on and off to get AC energy that is later directed to a rectifier for filtering.
- Programmable power supply: It’s an advanced power supply that comes with a remote control device that lets you make adjustments hands-free. With such a remote, you can change the voltage, frequency and currency.
- Uninterruptible power supply (UPS): This type of power supply gets energy from an AC power source and keeps a fraction of it in a battery. When electricity goes off, the power that is held in the battery is released to be used by the components. This system is commonly used in computers to prevent users from shutting down their computers unceremoniously because it can eventually cause system hardware to be damaged.
- High voltage power supply: Just like its name suggests, this power supply delivers thousands of voltages. It is therefore suitable for heavy commercial users. Due to the risk of electrification, this device comes with a special output connector that is heavily insulated to protect the user in the event of an accidental touch.
Uses of Power Supplies
Power supplies are used in welding workshops to join metals together. Additionally, every computer comes with a power supply for breaking down AC energy into DC for different devices such as the disk drive, floppy drive and the motherboard. Besides that, power supplies are used in electric automobiles to change energy that is stored in the battery into AC voltage. Airplanes need power supplies to convert their energy into AC voltage and vice versa. Power supplies are also found in phone chargers. They’re installed to change AC power to DC voltage.