reducing voltage

Discussion in 'General Electronics Chat' started by aimaldaudkhan, Aug 13, 2013.

  1. aimaldaudkhan

    Thread Starter Member

    Jan 25, 2013
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    how to reduce a voltage without using a regulator
     
  2. blueroomelectronics

    AAC Fanatic!

    Jul 22, 2007
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    How much voltage to how much voltage?
     
  3. studiot

    AAC Fanatic!

    Nov 9, 2007
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    And also what type of voltage?

    You can, for instance, halve the power by putting a diode in series with the power line.
     
  4. WBahn

    Moderator

    Mar 31, 2012
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    Are you sure you don't want to oxidize the voltage? :D

    Seriously, though, haven't you figured out by now that you can't just give some vague question and expect anyone to be able to answer it with any degree of usefullness?

    If you want to only reduce the voltage and not pull any current from it (as is commonly the case when making reference voltages), then you have one set of possibilities. If it is a DC voltage versus and AC voltage, then you have another set? If you are pulling much current at all from it, you have another set.
     
  5. wmodavis

    Well-Known Member

    Oct 23, 2010
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    Use a resistor
     
  6. wayneh

    Expert

    Sep 9, 2010
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    That presumes that a current is flowing. The OP hasn't said anything about current.

    I'd say, just change the reference point. Voltage is an arbitrary number.
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
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    Unplug it.
     
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  8. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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    Clearly not.. Along with the other 98% of the population..
     
  9. Shagas

    Active Member

    May 13, 2013
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    Poor Op is probably a newbie and doesn't know that the current is a variable in this question.

    TO OP:
    If you just want a reference voltage then you can use a voltage divider using 2 resistors.
    Google voltage divider or check it out on this forum.

    If you are planning to pull current , in other words if you want a lower voltage to power something like a light or motor then a voltage divider is bad because the voltage will shift and hence you will need a more complicated circuit which stabilizes itself when the voltage shifts which is what a voltage regulator Ic does .

    How about giving more details on what you want to power , why you want to lower you voltage etc etc etc then maybe someone can give a better solution. Or one at all
     
  10. Papabravo

    Expert

    Feb 24, 2006
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    How about a resistor, a zener diode, and a PNP transistor?
     
  11. ian field

    Distinguished Member

    Oct 27, 2012
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    You could string a load of diodes in series - about 0.7 - 1.0V per diode depending on current and diode rating.

    Or you could switch it on and off rapidly - you can follow that with a LC filter to get a steady voltage - they're quite tricky to set accurately - unless you include feedback, but then you have a regulator.
     
  12. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I once had to do it on a mobile DC generator putting out 240vdc.
    I need 12vdc for a simple low current field sensor circuit.
    I ended up using a 7.5k 20w resistor, 12v 1n4748 zener and a 100μf Cap.
    Not very efficient but worked well for many years.
    And still going strong.
    Max.
     
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  13. wmodavis

    Well-Known Member

    Oct 23, 2010
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    You can only accurately answer a question based on what information was presented by the OP in the question. Any more is pure conjecture and an attempt at mind reading which many are much better at than me. One of the most important solutions to electronic questions is clear communication. I'm not sure what is the solution to poor communication.
     
  14. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    Use a voltage divider.
     
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  15. aimaldaudkhan

    Thread Starter Member

    Jan 25, 2013
    38
    0

    yeah i just forgot about zener diode :) bow am using it :) thanks for helping
     
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