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tikbalang

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Posts posted by tikbalang

  1. check your bios. newer motherboards allow power up by:

    a. scheduled time set in the bios
    b. triggering the modem
    c. triggering the LAN card
    d. triggering the mouse
    e. triggering the keyboard
    f. triggering a usb device

    bioses can also set the power state upon AC power loss to:
    a. RESUME - start up when ac power is restored
    b. STAY OFF

    if yours can only stay off, you need this:
    http://www.pealefamily.net/tech/newmame/captrick/

    it switches on the pc as if someone pressed the power button.

    i would recommend triggering the modem. similar to ben23's suggestion but without using a relay device. it only requires the pc to be connected to a phoneline thru a modem. of course the bios and OS must also support this. for win2k/XP, you need to set the modem to bring the pc out of standby (device manager).

    http://img219.imageshack.us/img219/6540/poweruptt8.gif
    poweruptt8.th.gif


    to turn the pc on:

    1. dial the number modem is connected
    2. modem gets RING, triggers pc
    3. pc executes login/startup scripts
    4. you access and shutdown the pc using remote software

    if the modem is external, it has to be always ON to monitor the line.

    start --> turn of computer --> standby
    i am curious as to how you define standby. to me, standby = hibernate, where the pc is restored to its last ON state. i am unfamiliar with this as i do not use this feature.

    start --> turn of computer --> turn off
    in shutdown, the pc and monitor is still using power, unless disconnected from the mains, much like a TV turned off via remote (uses about 5W and evidenced by the leds momentarily turning on when plugged in).

    good luck on your project.

  2. checkout the links to other jukebox players at the bottom of celamantia's page.

    celamantia's support forum is located here:

    http://forum.arcadecontrols.com/index.php/board,27.0.html

    there is another audio player for dos that is worth mentioning:

    http://mpxplay.sourceforge.net/

    this one is geared towards turning old pc's into a dedicated audio player, as it can use a 4-line lcd display thru the lpt port.

    good luck with your project. feel free to pm me.

  3. this might interest you:

    
    DOSCab/WinCab Jukebox is an MP3 and OGG Vorbis player, designed for use in DOS or Windows based MAME cabinets or as a standalone home jukebox. It is designed to operate as a true jukebox, and not a media player. It is a complete jukebox construction set which can be completely re-skinned and controlled via keyboard, keyboard encoder, gamepad, mouse, or touchscreen.
    
    http://webpages.charter.net/celamantia/jukebox/
    
    



    for the dos version, you will need an soundblaster compatible sound card.

  4. i am using a constant current source (see below) as a simple charger. this was posted before and somebody suggested that c4 be removed and i did that in the actual circuit. input is 18v @ 1A dc. output is 500mA or 750mA to charge 2 up to 8 AA cells in series.

    i need a charging light that will indicate good contact between the cells and the charger. it has to keep the led at 20mA even when the number of cells at charge is varied.  i have thought of the second circuit, in series with the cells, but i think it will work only for a known number of cells, if it will work at all.

    thanks in advance.

    post-13054-14279142836778_thumb.gif

    post-13054-14279142837052_thumb.gif

  5. the quick and dirty formula for constant current charging is:

    (cell capacity mAH/constant current mA) * 1.4 = charging time H
    

    so, for a 2500mAH cell, charged at 500mA: (2500mAH/500mA) * 1.4 = 7 hours during charging the cell remains cool to barely warm. when it is about to reach the end of the charging time it suddenly becomes very warm to very hot. at this point they are fully charged. you need to get the average CHARGING TIME of the cells. make sure they are discharged, charge them one at a time at a known constant current, then get the average. you have to disregard the bad cells. check the TEMPERATURE every half hour or so to know if they are "fully charged". reversing the formula:

    (charging time H / 1.4) * charging current mA = cell capacity mAH
    



    so if you charged for 9 hours at constant current 250mA:

    (9H / 1.4) * 250mAH = 1607.1428571428571428571428571429 mAH


    *** 1.4 is a constant derived from charging C10 for 12-16 hours (standard charging). i used 14 hours because it is the median of 12 and 16.


  6. Hi Gogo,
    Protection diodes are needed if the output or ADJ terminal has a big capacitor and if the output voltage was higher and if the input or output are suddenly shorted. They aren't needed in this circuit.



    how can protection diodes be applied for constant current circuits like this?

    post-13054-14279142547945_thumb.gif

  7. http://siliconchip.com.au/

    the trick here is to use two different browsers. this is to keep your cache and cookies separate. i use offbyone to search the site for article titles. to get the full articles, i google with opera using keywords "silicon chip" + title of article, without the quotes and (+) symbol, and click on the google result. this is good for about 5 articles afterwhich, you're asked to pay for the article. i just restart opera.

    http://offbyone.com/
    http://opera.com/

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