Electronic

Discussion in 'The Projects Forum' started by Siyom, Aug 13, 2012.

  1. Siyom

    Thread Starter Member

    Aug 9, 2012
    33
    0
    Any other electronic switch besides FETs and Transistor?I'm using a microcontroller to switch between 2 states and i need an electronic switch that'll be controlled by the MCU no fets
     
  2. mcasale

    Member

    Jul 18, 2011
    210
    12
    What are you doing? How much current are you switching?

    Why do you dislike FETs? They are your friend.
     
  3. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    There is the bidirectional analog switch.
     
  4. Siyom

    Thread Starter Member

    Aug 9, 2012
    33
    0
    I'm switching currents that are less than a 1A,probably 500mA,and its for a dual slope integrator,thing is i can't get the PMOS to switch on low voltage
     
  5. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    Sounds like you don't have a firm understanding of Vgs and how it relates to a PMOS device being hooked up. Tell us what you think you know and we'll tell you if you are correct.

    Better yet why not give us a schematic drawing -- yeah, a schematic, that's the ticket!
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    You probably need logic level power MOSFETs. They are basically voltage controlled switches, where bjt's (standard bipolar junction transistors) are current controlled; current through the base controls a larger current through the collector.
     
    Last edited: Aug 13, 2012
  7. Siyom

    Thread Starter Member

    Aug 9, 2012
    33
    0
    Sorry i tried uploading an image but i couldnt,What i want to do is use the MCU to control which state is switched on,in the case of a fet,the MCU would send a high to the gate of the fet and it would switch on the first state.There are two fets NMos and PMos,the Pmos would be switched to the second state when the MCU sends a Low but this isnt happening at all.Nmos is working properly plus Pmso is not working at all.That what i atleast though it should b doing
     
  8. DickCappels

    Moderator

    Aug 21, 2008
    2,648
    632
    There are also the Triac, the SRC, the GTO-SCR (Gate Turn-Off), IGBT (Isolated Gate Bipolar Transistor), in special cases you can use a tunnel diode. If you can use higher voltages, there is the humble NE-2, Thyrotrons, and a variety of vacuum tubes, the triode being the fundamental case. For some applications a relay is all that is needed.
     
  9. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    The PMOS not working at all suggests that the source and drain are backwards. The Source should go to the supply, the drain should go to the load and when Vgs is negative WITH RESPECT TO THE SOURCE the PMOS part WILL conduct. It the source and drain are reversed then the gate must go negative, with respect to the source, to turn the PMOS FET on. Most MCU devices cannot produce a negative (below ground) voltage. RTFDS

    So what is the problem with uploading an image?
     
  10. Siyom

    Thread Starter Member

    Aug 9, 2012
    33
    0
    Ok thanks i'm going to look into that
    When i try to upload images i click on the icon that read "insert image" but i do not have the image on a URL but have it on my drive that's why i cant upload is there any other way
     
  11. Papabravo

    Expert

    Feb 24, 2006
    10,137
    1,786
    You don't use "Insert Image", you use attachments. This is the paper clip icon with the little drop down arrow. That should resolve your image upload problem.
     
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