PIC powered by capacitor for 0,5 second

Closed Thread
Results 1 to 19 of 19

Hybrid View

  1. - 22nd August 2007, 22:09 #1
    flotulopex's Avatar
    flotulopex
    flotulopex is offline Senior Member
    Join Date
    Aug 2006
    Location
    SWITZERLAND (french speaking)
    Posts
    938

    Did you find this post helpful? Yes | No

    Default

    It's a gadget for a car.

    I'll use a 7805 to make a clean +5VDC.
    Roger
  2. - 22nd August 2007, 22:48 #2
    Luciano's Avatar
    Luciano
    Luciano is offline Senior Member
    Join Date
    Oct 2004
    Location
    Italy
    Posts
    695

    Did you find this post helpful? Yes | No

    Default

    This is what happens with 1000 μF and a load of 1.62 mA.



    Luciano
  3. - 23rd August 2007, 10:13 #3
    Ioannis's Avatar
    Ioannis
    Ioannis is offline SuperMod
    Join Date
    Nov 2003
    Location
    Greece
    Posts
    4,121

    Did you find this post helpful? Yes | No

    Default

    I suppose that a 4700 is the minimum capacitor to use. There are .5 and 1 Farad capacitors in low voltage now available to power RTC's instead of coin batteries. Why not use one?

    Take a look at http://catalog.digikey.com/scripts/p...?name=P6955-ND

    Ioannis

    P.S. By the way, nice instrument Luciano!
    Last edited by Ioannis; - 23rd August 2007 at 10:17.
    www.signalcom.gr
  4. - 23rd August 2007, 10:59 #4
    Acetronics2's Avatar
    Acetronics2
    Acetronics2 is offline Fanatical Contributor
    Join Date
    May 2004
    Location
    NW France
    Posts
    3,651

    Did you find this post helpful? Yes | No

    Default

    Quote Originally Posted by Luciano View Post
    This is what happens with 1000 μF and a load of 1.62 mA.



    Luciano
    Hi, Luciano

    Nice to see you back here !

    mmmmmmh, By the way ....

    You gave the PEAK current ... as it decreases with power Voltage.

    A JFET could have been a better current drain than the 2.7k.

    Were nice holidays, weren't ??? You're not totally back it seems ... LOL !!!

    Best Regards
    Alain
    ************************************************** ***********************
    Why insist on using 32 Bits when you're not even able to deal with the first 8 ones ??? ehhhhhh ...
    ************************************************** ***********************
    IF there is the word "Problem" in your question ...
    certainly the answer is " RTFM " or " RTFDataSheet " !!!
    *****************************************
  5. - 23rd August 2007, 14:45 #5
    flotulopex's Avatar
    flotulopex
    flotulopex is offline Senior Member
    Join Date
    Aug 2006
    Location
    SWITZERLAND (french speaking)
    Posts
    938

    Did you find this post helpful? Yes | No

    Default

    Hello Alain,

    Could you give me some more details about how to connect the transistor and even why this would be a better choice please?
    Roger
  6. - 23rd August 2007, 15:03 #6
    BobEdge's Avatar
    BobEdge
    BobEdge is offline Member
    Join Date
    Feb 2005
    Location
    Holmfirth England
    Posts
    116

    Did you find this post helpful? Yes | No

    Default

    Hi,

    If you have not done so already try turning off the brown out detect at the programming stage, this will stop the pic from resetting as the voltage drops. With a 2200uF cap that should work fine

    Regards
    Bob...
    Last edited by BobEdge; - 23rd August 2007 at 15:27.
  7. - 23rd August 2007, 17:29 #7
    Luciano's Avatar
    Luciano
    Luciano is offline Senior Member
    Join Date
    Oct 2004
    Location
    Italy
    Posts
    695

    Did you find this post helpful? Yes | No

    Default

    Hi Alain,

    Thank you for appreciating my midnight engineering!

    Best regards,

    Luciano
  8. - 23rd August 2007, 22:12 #8
    Luciano's Avatar
    Luciano
    Luciano is offline Senior Member
    Join Date
    Oct 2004
    Location
    Italy
    Posts
    695

    Did you find this post helpful? Yes | No

    Default

    Hi Roger,

    Try that:



    Best regards,

    Luciano

    EDIT: The Brown-out Detect Voltage (BVDD) is 2.025 — 2.175 V.
    Try first with the internal Brown-out Detector enabled.
    Last edited by Luciano; - 23rd August 2007 at 22:21.
« Previous Thread | Next Thread »

Similar Threads

  1. How can a battery powered PIC turn itself off?
    By tekart in forum mel PIC BASIC Pro
    Replies: 8
    Last Post: - 9th August 2012, 10:44
  2. SMS via pic
    By kenandere in forum GSM
    Replies: 15
    Last Post: - 10th March 2010, 10:00
  3. pic to pic ir link versus wired link : help please anyone
    By xnihilo in forum mel PIC BASIC Pro
    Replies: 13
    Last Post: - 30th May 2008, 21:01
  4. Pic powered from USB?
    By Squibcakes in forum USB
    Replies: 5
    Last Post: - 26th June 2006, 00:03
  5. Serial Pic to Pic using HSER
    By Chadhammer in forum mel PIC BASIC Pro
    Replies: 5
    Last Post: - 11th March 2005, 23:14

Members who have read this thread : 0

You do not have permission to view the list of names.

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts

Forum Rules