most reproducible pots

Discussion in 'General Electronics Chat' started by dcd528, Nov 8, 2016.

  1. dcd528

    Thread Starter Active Member

    Jul 28, 2011
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    I have used multiple potentiometers in the past and am looking for one for a new project. It is a simple oscillator circuit with two transistors. I'm a bit confused about how the pots are rated. There is the tolerance rating, my understanding is that this represents how close to the stated resistance the pot really is. Is there a parameter that indicates how reproducible the setting is? I want something that when set to say 5 is as close as possible to that value each time I set it. I am looking for something around 5 to 10 K for use in a battery operated circuit, 5V and 0.5A would be fine.
    thanks
     
  2. dl324

    AAC Fanatic!

    Mar 30, 2015
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    Aside from using a multi-turn pot, you have control over resolution in your design.
    You say you want a 5-10K pot, but what is the resistance range you really need? Pots are generally low wattage; you're not going to be able to run 500mA through a 10K pot. If you do it through part of the resistance, take care not to burn it up.

    Better suggestions if you post a schematic.
     
  3. MrChips

    Moderator

    Oct 2, 2009
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    Multi-turn pots are very reproducible. For critical applications you may want to consider a digital pot.
     
  4. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What oscillator circuit do you have that needs 0.5A?
     
  5. crutschow

    Expert

    Mar 14, 2008
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    0.5A through 5kΩ is 1.25kW so I suggest you tell us what the pot actually does. :rolleyes:
     
  6. dcd528

    Thread Starter Active Member

    Jul 28, 2011
    42
    1
    sorry for the late reply. 0.5A is a guess and obviously way off. It is a basic oscillator circuit from Forrest Mims book. Two transistors a cap and some transistors.
    I did a project a while back and had a thumbwheel pot (cheap one, $1.50 I think) and it seemed that it isn't reproducible. A setting of 5 doesn't always give exactly the same results, so it seems.
    So I want to do an oscillator and have the pot give very reproducible results.
    As soon as my phone charges I'll take a pic and post the circuit.
     
  7. dl324

    AAC Fanatic!

    Mar 30, 2015
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    Use a better quality pot. You over paid anyway. A dollar should get you a very good quality CERMET single turn pot.
     
  8. drc_567

    Senior Member

    Dec 29, 2008
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