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current sinking pulse

TobiasTobias Posts: 95
edited 2008-04-06 17:12 in BASIC Stamp
I am getting a flow meter, its voltage ranges from 5-24 vdc and the output is a current sinking pulse of 6-24v it also gives you an option of hooking it up npn type or pnp, how is the best way to go about this? I don't think I can hook it up direct to the bs2 and use the pulse-in command because its voltage range is to high or could I use a in line resistor? Your responds will be greatly appreciated Thanks
Thank You Toby

Comments

  • marzec309marzec309 Posts: 146
    edited 2008-04-05 15:12
    Do you have a data sheet for your flow meter?
  • TobiasTobias Posts: 95
    edited 2008-04-06 00:15
    160˚ F (70˚ C)
    150 PSI (10 bar)
    +1% of full scale
    input: 5-24 Vdc, 2 mA min
    output: Current sinking pulse, 6-24 Vdc
    Yes Thats about all the useful information I''ve got.
    Thanks Toby
  • TobiasTobias Posts: 95
    edited 2008-04-06 00:16
    160˚ F (70˚ C)
    150 PSI (10 bar)
    +1% of full scale
    input: 5-24 Vdc, 2 mA min
    output: Current sinking pulse, 6-24 Vdc
    Yes Thats about all the useful information I''ve got.
    Thanks Toby
  • jmalaysiajmalaysia Posts: 97
    edited 2008-04-06 01:04
    I did a little looking on this site-

    http://www.globalw.com/downloads/SMProduct/spx.pdf

    Surprisingly it had little info more than what you already provided! First off, 24vdc is a pretty common number for controllers, so I would suspect it is telling you that it is capable of sinking up to 24vdc. I doubt it is actually generating the 24vdc- it can just pulse it low. It looks to me like you would be safe powering it with 5vdc and then letting it sink a pulled up stamp pin. Just keep a fire extiguisher handy!
  • marzec309marzec309 Posts: 146
    edited 2008-04-06 17:12
    From what I've seen so far in this post this circuit should get you up and running.

    FlowMeter.jpg

    Though there are a couple of ways you could go about reading the sensor. You could use the PULSIN Command (PULSIN 0,0,Flow), like you suggested but this wouldn't yield very accurate results. I would suggest you use the Count camand. like Count 0,1000,Flow.
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