Stuff I Don’t Get- Why PC Laptop Cords Need the Awkward Two Piece Power Brick Thingie


In this day and age they haven’t figured out how to streamline the whole cord set-up? If you’re traveling with a laptop obviously you want to travel light. The bulky cord set-up just seems like a no-brainer for streamlining to make more user friendly. What computer guru knows the reason for the bulky brick?


  • All desktops come with a power supply built into the case, with the limited space in a laptop, the power supply cannot fit inside and, therefore, must be on the outside. It’s unfortunate, but it’s a price you pay for your convenience of carrying your computer with you. It might be helpful to buy a second power supply to keep in your office.


  • Well, actually the wizards at Apple have figured it out. Macbooks have a small chunky charger that plugs into the outlet, and nothing else between it and the computer. One of the many reasons why we love our Macs….


  • Those annoying appendages are called “Dongles” in the tech world. They could be a cumbersome power brick, or hardware for an adapter that plugs externally into your PC, that the computer should have been designed to do in the first place, I have observed, with the evolution of computers, that newer models incorporate the function of the “Dongle.” However, as technology progresses, new “Dongles” are invented for even the latest computers. That’s progress.


  • And the long answer by Rubber Duck: That brick contains a transformer. Since most modern laptops require between 40 and 90 watts of juice the transformer has to be big enough to contain two coils of wire that can handle 120 volts AC and 40 watts on the other side. The primary coil is fed by the 120 volt AC which sets up a magnetic field which induces a lower current in the secondary coil. That is the “transformation”. Then the power also needs a rectifier that changes it to DC and some filters to smooth out the pulsing DC to smooth direct current that the laptop innards want. It could be in the laptop but that adds to the weight and it is also the piece of electronics that most frequently breaks so buying another dongle or brick is easier than digging it out of the laptop.

    All electronics has gotten smaller but the transformer has to contain those two coils of copper wire. The big garbage can sized thing up on the telephone poles does the same thing, stepping 50,000 volts AC down to a nice house current of two 120 volt AC lines.

    Your landline rechargeable phone only needs 5 volts DC so the transformer is that mouse sized dongle that plugs into the wall. Laptops need more juice so the physical size has to be bigger. I think Michael Faraday made a law centuries ago that still has to be followed.

    Bill had the best short answer, buy a Macintosh. Apple has been making pretty power dongles for years. It costs money to squeeze those coils into a cute white cube but worth it. The smallest MacBook Air only requires 40 watts so the power cube is quite small. All laptops will eventually follow Apple’s lead switching to solid state SSD drives instead of spinning drives, getting rid of CD drives and thinner low power monitors.


  • Also, by making it a 2 piece design, it helps with making it more international, only the half that needs to plug into a different type of outlet needs to be changed when shipping to different countries. The transformer half can stay the same.


  • It is easier to get UL and electrical approval for the two piece supply. Also, you can have a more universal design in the charger, and just have different cables plugging into the computer. This is from my business partner, who designs lots of electronics, and specifies batteries and power supplies. It apparently is that simple an answer.


  • This is all Tesla’s fault! If Thomas Edison had his way we wouldn’t need the power adapters because there would be a huge DC power generator building every other block!


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