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Short Circuit

cpwemscpwems Posts: 2
edited 2005-02-20 17:33 in BASIC Stamp
I am trying to use the BS2 as a switch.· Say have P0 and P1 create a short circuit with about 1.5uA (micro amps) going through it and potential of about 76mV.· I would like this to be done programmatically, hopefully without having to use a bus switch or something like it, otherwise I know how I could use a bus switch. ·I have 5 lines that can short to a possible 8 lines for 40 combinations.· Any help would be appreciated.

Comments

  • RickBRickB Posts: 395
    edited 2005-02-19 19:32
    It sounds like you are describing a multiplexer or crosspoint switch. Check out Maxim Dallas

    http://www.maxim-ic.com/[noparse][[/noparse]url]

    Rick
  • agentileagentile Posts: 101
    edited 2005-02-19 20:06
    I agree that you are trying to create a multiplexer.· These are common, inexpensive, and easy to use chips.· In fact, with a few logic gates, you can make one.· I have included a link which shows how to make a 2 channel mux.· You could easily buy a chip for a couple of dollars which will accept more channels.

    http://www.play-hookey.com/digital/multiplexer_two_input.html



    AG
  • cpwemscpwems Posts: 2
    edited 2005-02-19 20:32
    Thanks for your guys help, but I need it to really act like a switch, something like TI SN74CBT3125D, where I can enable or disable to switch.· I know I can use this actually device but was just wondering if I could do it using the BS2.
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2005-02-19 21:23
    CPWEMS -

    The TI SN74CBT3125D can be driven by a Stamp, but a Stamp can not act in manner to replace such a device directly. Among other things, that device will support a constant current of 125 mA which is far in excess of what the Stamp current rating is.

    The SN74CBT3125D is esentially nothing more than a transistor array. In fact, the Stamp uses a transistor array in its construction but it can not be used separately.

    Regards,

    Bruce Bates
  • agentileagentile Posts: 101
    edited 2005-02-20 17:33
    What if you use a multiplexer to drive a bank of relays?· If you only need 125mA, you could just use a bunch of NPN transistors, and the output of the multiplexer can feed the base current of your transistors.·



    AG
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