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Reverse Polarity Protection From A 9V Battery — Parallax Forums

Reverse Polarity Protection From A 9V Battery

MooneyguyMooneyguy Posts: 77
edited 2014-10-13 08:56 in BASIC Stamp
If I Inadvertently touch the 9VDC battery terminals to the Basic Stamp 2 module, will it cause damage to the circuit? If so, is there a simple circuit you can suggest I can add that will protect it from damage?

Comments

  • MooneyguyMooneyguy Posts: 77
    edited 2014-10-09 14:04
    Looks like I need an answer to the question "Will the Basic Stamp 2 circuit get damaged if the 9 VDC battery is reversed"?

    Seems I just found circuit protection information at :
    http://forums.parallax.com/showthread.php/102071-Reverse-Polarity-protection ...102071-Reverse-Polarity-protection
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-09 16:47
    I'm not clear on which pins you connected the 9V battery to. It is important to know what leads were connected where on the module to really answer the question.
  • Dave HeinDave Hein Posts: 6,347
    edited 2014-10-10 09:25
    Mooneyguy wrote: »
    If I Inadvertently touch the 9VDC battery terminals to the Basic Stamp 2 module, will it cause damage to the circuit? If so, is there a simple circuit you can suggest I can add that will protect it from damage?
    The answer is YES! The Basic Stamp 2 module will be damaged.

    No, there is not a simple circuit that would protect the Basic Stamp 2 module from being destroyed if somebody touched random pins to the terminals of a 9 volt battery. There is also no circuit that will protect the Basic Stamp 2 module from damage if you step on it. Just don't do that!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-10 10:06
    Dave Hein wrote: »
    The answer is YES! The Basic Stamp 2 module will be damaged.

    No, there is not a simple circuit that would protect the Basic Stamp 2 module from being destroyed if somebody touched random pins to the terminals of a 9 volt battery. There is also no circuit that will protect the Basic Stamp 2 module from damage if you step on it. Just don't do that!

    Dave,

    It may no be so cut and dry. The OP mentioned 9V battery snaps. That implies a dev board was used and not just a module connected to the battery. I would have to check the specific board to see if the regulator on that board has reverse polarity protection and if that regulator was used to power the module on that board.
  • Dave HeinDave Hein Posts: 6,347
    edited 2014-10-10 12:29
    Yes, I know. It's just that this is the third thread that the question has been asked, and we still don't know exactly what the scenario is. I thought I had fully answered the question on one of the other threads, but apparently my answer wasn't sufficient.

    Mooneyguy, please tell us exactly which circuit or board you are talking about, and I'm sure we can answer your questions.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-10 14:31
    Trying to answer across multiple threads is an effort in futility. Seems I have visited two already myself. So while we wait for the details I will say that a 9V battery connected in reverse to the VIN and GND pins on the BASIC Stamp 2 should not damage it. On the Board of Education the BASIC Stamp is powered through VIN, so the battery snaps connected to the VIN and GND pins. On some boards like the Super Carrier Board, the BASIC Stamp is powered by VDD supplied by the board's regulator.
  • doggiedocdoggiedoc Posts: 2,240
    edited 2014-10-10 14:38
    Chris Savage wrote: »
    Trying to answer across multiple threads is an effort in futility. ...
    My bad. I suggested he start his own thread, since the other thread had been inactive since 2008.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-10 15:02
    doc, no big deal. If I had noticed the threads before the replies I would have moved everything into a single thread. I haven't checked to see where the 3rd thread Dave mentioned is, but hopefully we'll get this figured out soon. :cool:
  • doggiedocdoggiedoc Posts: 2,240
    edited 2014-10-10 15:38
    I think we still need to know what board he's using.
  • MooneyguyMooneyguy Posts: 77
    edited 2014-10-11 23:57
    I think I messed everyone trying to help by splitting my replies across multiple threads. I apologize. There is more detail here which includes photos and schematics: http://forums.parallax.com/showthread.php/102071-Reverse-Polarity-protection

     I would like to know if I need a zener diode and also why I cant figure out how to make the bluetooth RN-42 module work with my Dell Windows 7 PC. I can live with a wired connection if I must.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-13 08:56
    As in my previous reply the Bluetooth to PC stuff will be overlooked until the original issue is solved. Otherwise we're just jumping all over the place. I am going to lock this thread and leave follow-ups to the other one to avoid further confusion.
This discussion has been closed.