AC Power supplies that have an oscillator for 60hz, 120hz,400hz,800hz

Discussion in 'General Electronics Chat' started by SamEricson, Apr 25, 2015.

  1. SamEricson

    Thread Starter Member

    Apr 25, 2015
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    Some AC power supplies have a built in oscillator that can change the Line frequency to 60hz, 120hz, 400hz, 800hz. Can I power a circuit board that is designed for 60hz and power it up with 400hz or 800hz or power a circuit board that is designed for 115 at 400hz and use a regular power supply at 115 vac at 60hz? What would I have change in the design to power a circuit board that is designed for 115vac at 400hz to work with a power supply that is 115vac at 60hz? is there any problems or it will work?
     
  2. Papabravo

    Expert

    Feb 24, 2006
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    I don't think you can change the line frequency. I think power supplies my work over some range of frequencies, but not in the way you described. If you supply power at some frequency besides the one it was designed for you may find that the transformer will get hotter than you might be comfortable with. Why do you ask?
     
  3. SamEricson

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    Apr 25, 2015
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  4. SamEricson

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    Apr 25, 2015
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    What components in a circuit determine what the line frequency should be for the circuit board to work? does any circuit board really care what the line frequency is?
     
  5. #12

    Expert

    Nov 30, 2010
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    post#3) not likely
    post#4) several of them.
    post#4b) yes.

    There is no way to just say, "Plug any frequency you want into any board you can find". It doesn't work that way.
     
  6. SamEricson

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    Apr 25, 2015
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    the circuit boards don't have a power supply. I will be using an external power supply to supply the 115vac voltage. The only difference is the line frequency will be different.

    The line frequency does what to a circuit? does it really matter if you change the line frequency? will it harm or damage components?

    I can't find in any electronic book what the line frequency really does or determines to a circuit board that is using an external power supply. The line frequency will pass through the +VCC and ground rails and cause noises or oscillations?
     
  7. #12

    Expert

    Nov 30, 2010
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    It depends on the circuit board.
    I've already told you the frequency matters. So did Papabravo.
    If you want to find out what happens to these unknown circuit boards, plug some in to random power frequencies and find out the many ways they fail and where the smoke comes out. If you want to know how power supplies work, look here:

    http://www.dogpile.com/search/images?fcoid=417&fcop=topnav&fpid=2&q=DC+power+supply+schematic&ql=

    Pick one, study the design, and you will see that each one is designed for a certain frequency. After you understand that every power supply is designed for the frequency it expects, you can still design one for 400 Hz and try plugging it into 60 Hz.
     
  8. SamEricson

    Thread Starter Member

    Apr 25, 2015
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    The circuit board doesn't have a power supply, it needs an external power supply

    Yes I understand if a power supply is designed at 115VAC at 400hz and you plug it into the wall at 115vac at 60hz the line transformer will be hot or cause damage to the line transformer i'm guessing.

    The filter caps, bridge rectifier or regulator don't can't if the line frequency is 60hz or 400hz or 800hz

    Are the filter caps designed for a cap value for the line frequency in power supplies? if the filter caps are valued for a line frequency of 400hz and you supply 60hz then the filter caps won't filter out the 400hz line frequency and you will have a large ripple voltage passing and going through the whole circuit board?

    The Circuit board under test that needs an external power supply. Most circuit boards are designed for 115vac at 60hz. Other circuit boards are designed for 115hz at 400hz.
     
  9. #12

    Expert

    Nov 30, 2010
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    I don't understand. The circuit board under test needs an external power supply, so get one and plug it in.
    Filter caps are designed for the frequency that is expected. Capacitors designed for 60Hz might work at 400 Hz, but I can't guess exactly what YOUR design requires.

    Why don't you just read the label and give the board what it is designed for?
    I can't guess about some unknown number of circuit boards that need an external power supply, or need 60Hz, or need 400 Hz.
    Why would you even want to plug a circuit board into the wrong kind of supply?

    There is no such thing as a universal answer that applies to all random circuit boards that you can find.
     
  10. SamEricson

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    Apr 25, 2015
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    Because I only have AC power supplies 115vac at 60hz and the circuit boards are designed for 115hz at 400hz. So i don't know if it will damage the circuit boards or not.

    I am "bypassing" the power supply section of the circuit boards or the circuit boards didn't come with a 115vac at 400hz power supply. By I'm bypassing the power supply at 115vac at 400hz is because if i plug in a power supply at 115vac at 400hz into a wall outlet at 115vac at 60hz what will happen?
     
  11. #12

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    Nov 30, 2010
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    It will burn up.
     
  12. SamEricson

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    Apr 25, 2015
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    any reason why? because the line transformers winding is for 60hz? i don't get it
     
  13. debe

    Well-Known Member

    Sep 21, 2010
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    This sounds like Aircraft electronics as they use 400Hz I think. This sounds like a poster some time ago that would post questions like this with very little details. Then the posts just went round in circles.
     
  14. BillB3857

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    Feb 28, 2009
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    It really does sound like Dexter, doesn't it?
     
  15. Papabravo

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    Feb 24, 2006
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    This power supply will tolerate a wide range of AC input frequencies. It does not do anything to those input frequencies except convert them to DC. The cost is at least ten times the cost of a normal power supply so you get what you pay for. Reread post#2, I said a power supply can be designed to work over a range of input frequencies. That statement was correct and unambiguous.
     
  16. Reloadron

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    Jan 15, 2015
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    It's a DejaVue of Billy Mayo (and other names) all over again. :) I'll offer up 10:1 odds.

    Ron
     
  17. Papabravo

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    Feb 24, 2006
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    We really need to stop feeding them.
     
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  18. Reloadron

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    Jan 15, 2015
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    And from the Great State of Michigan comes the voice of reason and common sense. :)

    Ron
     
  19. Papabravo

    Expert

    Feb 24, 2006
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    It's easy advice to offer, but much harder to follow in practice. Know this, I do.
     
  20. JWHassler

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    Sep 25, 2013
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    Agreed. And maybe find/destroy whatever interwebs entity it is that generates reasonable-sounding Anglo-American names for them.
     
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