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pwm command

TobiasTobias Posts: 95
edited 2007-08-29 21:08 in BASIC Stamp
····· I am using the bs2 to create a pulse width, It works good I can see it increase in voltage when it is told to, on my scope but what I am trying to do is control a 1 amp proportional valve now is it possible to control it with the bs2?
Thank-You
Toby

Comments

  • D FaustD Faust Posts: 608
    edited 2007-08-28 10:56
    You mean that the valve requires 1 amp, right?· You could, but you wouldn't be ale to do anything in the loop because the pwm stops when the command does.· You would have to use a transistor and the transistor would float with no pwm.· The PWMPal by parallax·would solve this problem.

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  • TobiasTobias Posts: 95
    edited 2007-08-28 18:25
    Is it possible for me to just run the valve at 2.5 volts with the cap and resistor curcuit? What kind of transistor do I need to use?

    Thanks

    Toby
  • D FaustD Faust Posts: 608
    edited 2007-08-29 12:36
    You would use a transistor with logic level turn on (5V), and that could supply 1 amp.

    What cap resistor circuit are you talking about?
    Voltage Divider?

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  • TobiasTobias Posts: 95
    edited 2007-08-29 18:29
    The one they show in the help menu 10k resistor and a .1uf cap I will try touse a tip41 transistor will that work?
    Thanks
    Toby
  • D FaustD Faust Posts: 608
    edited 2007-08-29 18:51
    I looked at the resistor capacitor circuit. You want it to maintain an analog voltage, correct? If you have the parts I would run some tests to see how often you have to give it fresh pwm. (It isn't stated on the page) It looks to me like that transistor would work, but I am not going to guanrantee you that it turns fully on at 5V because I am "datasheet challenged" myself.

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  • cyplesmacyplesma Posts: 76
    edited 2007-08-29 21:08
    Tobais,

    just a quick reminder always create you circuit with switches in place of the stamps output and leds in place of the stamp's inputs.

    If you have the transistor on hand and you create the circuit to replace the stamp's I/O with switchs /leds then use your test equipment to make sure it does what you want it too.

    If you haven't order/bought the transistor yet then maybe do a check on other electronic sites for that trans or one that will do what you want it do.

    I don't mean to sound dumb, but I know I often forget easy ways to check things.
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