What is DC Power Supply?


A Direct Current (DC) Power Supply is a type of power supply that exclusively and constantly supplies DC voltage. Although electrical power is usually transmitted, generated, and disturbed as AC, there are situations where DC Supply is essential. However, this is just a superficial answer. Before you can answer the question of what DC Power Supply is thoroughly, there are some basic information you need to know.

There are different definitions for Power, however the power which is going to be mentioned a lot in this article refers to electrical power. Electrical Power means flow rate of electrical energy in a closed circuit. There are 2 different types of electrical power. They are called AC and DC power. If current flows in alternating direction, then Alternating Current (AC) power is produced. If current flows in one direction only, then Direct Current (DC) power is produced.  

Tackling the question of what is a DC Power Supply is straightforward yet you need the basic electrical information before anything. If you are already familiar with the terms the previous parts might seem redundant for you. However, if you are a beginner, with your newly learned information, you can take a step back and try to thoroughly answer questions like, what is dc power supply and how to build a DC power supply.

Devices powered by batteries or similar other sources usually need DC power. The way DC power supply work is mainly related to which device they belong to. From cars to cell phones, these devices all have their own DC Power supply working on their own conditions.

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The difference Between an AC and DC Power Supplyac-dc-power-supply

AC and DC Power supplies are distinct from each other in many ways. However, all of those distinctions stem from the fact that their electrons flow in different directions.

Another difference between the two is their power transmission.

DC Power Supply generally uses batteries as power source, in contrary AC Power Supply utilizes outlets as power sources.

Besides all the differences, there are some ways AC and DC power supplies are similar. One of the similarities between the two is they both use regulators. The point of these regulators is to eliminate ripple voltage and smooth out the signal.

DC Power Supply Types

You should know by now that a DC Power supply supplies constant DC Voltage. They mainly use AC mains electricity as an energy source. However, its power source can be both DC Source and AC Source depending on its design. As a result, there are different types of DC Power supplies. AC-to-DC supply, Switched-mode Power Supply, Capacitive Power Supply and Linear regulators are each a different type of a DC Power supply. Let’s look at each of these different types of DC power supplies to get a better grasp on what DC power supply is.


AC-DC Power Supply


DC Power supplies converts the input voltage from AC Power sources. AC-DC Power supplies contain a rectifier and electronic filter to convert the energy into an unregulated DC Voltage. Most of the voltage is converted into DC however, some AC voltages remain. These are called ripple. Too much ripple can cause problems for the power supply.

Linear Regulator

Linear regulators convert a varying DC voltage to a lower DC voltage. To stop the current from reaching excessive amounts, Linear regulators provides a current limiting feature. Linear regulators can also reduce the ripple on the output voltage.

Switched-Mode Power Supply

A switched-mode power supply converts DC voltage into an AC current by switching DC voltage on and off at a high frequency. Cheaper, lighter, and smaller filter capacitors are used because of the high frequency switching.

Most Switched Mode Power Supplies contain certain safety measures such as crowbar circuit or current limiting. This is very important because if there is a extra amount of current power, it might harm the user and the device.

Capacitive Power Supply

Capacitive power supply, also known as transformerless power supply, can reduce the mains voltage to a smaller AC voltage.

Now that you have a basic idea about the types of DC Power supplies, now it is time to get to know them better. What better way to get to know a device than building it on your own? Let’s learn all about how to create a DC power supply, more specifically, a 12V Dc power Supply.

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How to make 12v DC Power Supply


Before you start to make a 12v DC Power supply, there are certain items and tools you need. Here is the list of items and tools you need to build a 12v DC Power Supply


Veroboard, Jumper wires, two, 100 nF capacitors1000uF – 4700uF capacitor, 1uF capacitor, LM7812 regulator, and a transformer with 14v-35v output and 100mA-1A current output.

                You can also get an heat sink to produce a 1A output current.


Wire Cutters, Wire Strippers, Hot Glue, Soldering Iron, and your usual working tools you are comfortable with.

 To build a proper 12V DC Power supply, you need to know your LM7812 schematics. You can find them on the internet. If you are already familiar with those, you are ready to build your 12V power supply!

First thing you need to do is trim your Veroboard tracks. You do not need all of it and working on a smaller Veroboard track will be helpful.

One thing you need to be careful about while you are making your power supply is solder joints. If you do not, you might end up solder bridges which will cause your power supply to not work.

After you finish soldering, your 12V power supply is ready to test! You can test it with a multimeter to make sure its 12V.

Do not forget to put it somewhere non-conductor because even if you are the one who built it, it can still shock you.

You now know how to build the most basic 12V DC power supplier. You can use it anywhere you want, just be careful with it.

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