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A function generator that cannot kill you? Very low currents.

  1. Oct 28, 2014 #1
    Hi, I am looking for a function generator that if you hooked up to yourself, wouldn't kill you. I need something that can output very low currents through the skin without harm. Honestly a 9V battery causes too high of a current for my purpose, but I do need to very finely tune the current. Can anyone help?
     
  2. jcsd
  3. Oct 29, 2014 #2

    sophiecentaur

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    I'm not sure what you actually want but function generators, in general, are not lethal. The only way it can give you discomfort is if you stick the leads across your tongue. That will jolt you but still not kill you. Output volts are normally only a few Volts.
    What is your actual application? Putting a high value of resistor in series with the 9V battery can limit the current to as low as you want. A 9MΩ (megaOhm) resistor in series with 9v will give 1μA (microAmp). Is that low enough for you? :) How do you intend to measure these currents - and what do you want them to do for you?
     
  4. Oct 29, 2014 #3
    How is 9 V output supposed to be dangeorous for humans at any frequency?
     
  5. Oct 29, 2014 #4

    sophiecentaur

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    Embed it in your brain, perhaps????
     
  6. Oct 29, 2014 #5
    Haha
     
  7. Oct 29, 2014 #6

    sophiecentaur

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    Attach the electrodes Igor.
    Yeth mathter.
     
  8. Oct 29, 2014 #7
    Licking of 9 V AC can be quite unplasant too o0)
     
  9. Oct 29, 2014 #8

    Doug Huffman

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    Transcutaneous Electrical Nerve Stimulation devices, also neuromuscular electrical stimulation.

    I had Bells (facial) Palsy as an adolescent with NMES prescribed to maintain muscle tone in my face while recovering.

    More recently I impinged my (coincidentally) Bell's Long Thoracic Nerve enervating my Rt Anterior Seratus and giving me an winging scapula. Diagnosis involved electromyography to determine the extent of the insult injury.
     
  10. Oct 29, 2014 #9

    sophiecentaur

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    I have to wonder what exactly the OP has in mind!!!

    I remember, as a lad, hooking up a bicycle dynamo (AC) to an ignition coil and having fun in our garage. But I was an eejit in those days. (Nothing changes)
     
  11. Oct 29, 2014 #10
    There are also devices for sexual stimulation of women. One electrode in vagina-other electrode in rectum. Dunno about voltage output and waveform though.
     
  12. Oct 29, 2014 #11

    sophiecentaur

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    Back to my family garage in 1961!!!

    Sad to report that the experiment was of no great merit. But, at that age, anything was better than nothing. lol
     
  13. Oct 29, 2014 #12
    Thank you for all your silly comments I think I just feel in love with this forum, haha! I'm sorry for my limited knowledge on this stuff, I'm a physics major however I have a few meetings next week to discuss if I will be taking on EE as a 2nd major, minor, or focus.

    Anyways, any recommendations of a function generator to buy, preferably affordable. I really hope I can easily tweak currents from 0.0002A to 0.001A.
     
  14. Oct 29, 2014 #13

    berkeman

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    All kidding aside, you really can hurt yourself if you don't know what you are doing, and start putting electrodes on your body. Can you say more about what you are wanting to do? Buying a commercially-available TENS device may be your best option. They have come down in price a lot over the past few years...
     
  15. Oct 29, 2014 #14

    berkeman

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    BTW, I have a friend of a friend who knows somebody who was working on an EEG device design, and decided to try connecting a 9V battery momentarily to a couple anterior electrodes. Let's just say that he won't be doing that again any time soon (hurt like hell) o0)
     
  16. Oct 29, 2014 #15
    Well, one can get hurt by 9 V battery in a various ways, and with very little aditional equipment. For instance, << Interesting example deleted by Mentor as being a bit dangerous... >>
     
  17. Oct 29, 2014 #16
    You might consider just using an IC waveform generator like an XR-8038. This'll let you get a triangle, sine, or square wave. They're significantly less expensive than a purpose made function generator. The voltage you get out is limited by what you put in, so if the whole thing is driven with a couple of AA batteries, you're not gonna deliver a ton of power. If you're concerned about current, you can always limit it with resistors. If you're set on a function generator, don't worry too much on the current, as you can limit current by adding components to the circuit. Just be sure to measure where it's at with a multimeter if you're gonna do weird body stuff with it. Sorry, but I don't know brands well.
     
  18. Oct 30, 2014 #17
    Can't be that dangerous if it's on the internet.:oops:
     
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