Ne555

Discussion in 'The Projects Forum' started by ramcaress, Mar 1, 2010.

  1. ramcaress

    Thread Starter New Member

    Mar 1, 2010
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    i would like to know if there's a difference between LMC555 and NE555, or something that is CMOS type 555, i built this circuit from EME systems, SMX soil moisture interface but it didn't work, the electronic shop here sells only NE555, pls help, thanks a lot
     
  2. russ_hensel

    Well-Known Member

    Jan 11, 2009
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    Can you google and find the data sheets?
     
  3. SgtWookie

    Expert

    Jul 17, 2007
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    1,728
    The LMC555 is a CMOS version. It can operate at lower voltages than the NE555 does, and the output is able to reach nearly to both power rails (+V, GND).

    The NE555 needs around 5v to operate, but some circuits won't work with a supply that low, particularly if the timing capacitor is being charged/discharged by the output (pin 3).

    Post the schematic of the circuit, that is the quickest way to get help.
     
  4. ramcaress

    Thread Starter New Member

    Mar 1, 2010
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  5. SgtWookie

    Expert

    Jul 17, 2007
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    Sorry, it's not going to work on 3.3v with an NE555.

    Are you in the USA? If there is a Radio Shack store nearby, they usually have TLC555 timers in stock. Don't let them sell you anything else, as a standard NE555/LM555/SE555 won't work.
     
  6. ramcaress

    Thread Starter New Member

    Mar 1, 2010
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    thanks a lot, im goin to look for a cmos type 555, i analyzed the circuit several times but can't look on some errors, its clear now that a standard NE555 won't substitute the cmos type, thanks a lot, more power:):):)
     
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