Clarification on inverters?

techtiatechtia Posts: 144Member
The exam cram practice exams says it converts AC to DC but other sources says it converts DC to AC. Is this an error in the exam cram practice test?

The exam cram says power inverter but when I googled it, a power inverter is an inverter, no difference. Help thanks

Comments

  • QueueQueue Posts: 174Member ■■■□□□□□□□
    Alternating current comes out of the wall. 120V here in US usually for most everything in your household. There is also 220V for bigger appliances.

    Computers use Direct current.

    So in practice its AC to DC for a test question.
  • techtiatechtia Posts: 144Member
    What is a Laptop Inverter? (with picture)

    Is that site wrong? They said DC to AC
  • QueueQueue Posts: 174Member ■■■□□□□□□□
    I misread your question.

    AC comes from a wall socket from the power company.
    DC is from sources such as batteries.

    Your laptop would have an AC converter that you plug in the wall and then changes to DC with a "converter" to charge the battery. The battery is also then DC to your computer because the things inside require the specific voltages. LCD requires an inverter because it needs AC.

    By definition an "inverter" converts DC to AC.

    Does exam cram really say that? You might be thinking of a converter instead of inverter.
  • techtiatechtia Posts: 144Member
    2cyhzz7.jpg
  • techtiatechtia Posts: 144Member
    Sorry the screen shot above got sized down so small, just keep enlarging the image and you should be able to read it.

    I'm just confused, hope someone can help me. Thanks

    Ignore the "You answered this question correctly" I pressed the button to show the answer :D
  • techtiatechtia Posts: 144Member
    Queue wrote: »
    I misread your question.

    AC comes from a wall socket from the power company.
    DC is from sources such as batteries.

    Your laptop would have an AC converter that you plug in the wall and then changes to DC with a "converter" to charge the battery. The battery is also then DC to your computer because the things inside require the specific voltages. LCD requires an inverter because it needs AC.

    By definition an "inverter" converts DC to AC.

    Does exam cram really say that? You might be thinking of a converter instead of inverter.

    From your reply, the outlet is AC powered and the laptop requires DC to run, so an inverter does convert from AC to DC.

    The laptop needs DC power to run? or is it AC Outlet > DC Battery > then back to AC? LOL sorry for all the mess
  • cyberguyprcyberguypr Senior Member Posts: 6,721Mod Mod
    This is an awful question written by someone who is clueless about electronics. I can't think of any possible scenario where anyone would call an AC to DC device an inverter. As Queue said, the definition of an inverter is DC to AC. Things that change AC into DC could be a converter, rectifier, power supply, etc.

    Professor Messer references inverters in the correct context: "So behind that laptop screen are something called inverters that will take that DC power that’s coming into the laptop and converts it now into AC power that is used to power those fluorescent lights."

    Calling a laptop's power adapter an inverter is just wrong.
  • techtiatechtia Posts: 144Member
    This exam cram has been my go-to study method, that doesn't instill a lot of confidence in me taking this exam early next week.
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