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Christmas Lights!!!! - Page 2 — Parallax Forums

Christmas Lights!!!!

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  • skylightskylight Posts: 1,915
    edited 2008-12-31 18:18
    lboucher said...
    I never head of a Triac before. Was looking up a data sheet. Looks cool.
    Doesn't have any information on lifetime, does anyone know how long these last?

    Thanks
    Lucas
    If adequately protected by correct type of fusing and heatsinking they can last many many years, some of the triacs at work have been giving service for 20+years with no problems.
  • bennettdanbennettdan Posts: 614
    edited 2009-01-01 00:49
    Hey guys,
    Jon Williams did an article in Nuts and Volts magazine last year he used the Vixen control software and some EFX products to build his light display he uses Triacs and a zero cross detector Opto to not only control each channel on and off he can also dim each channel. He used the SX chips to bild his boards. The link has the code for the SX chips and the express PCB schematic and PCB layout you need expressPCB software to read it but its free to download.
    www.nutsvolts.com/downloads.php?63
    www.expresspcb.com/

    Also check out what this gu did for the prop contest he has 128 channels of lights.
    www.parallax.com/Resources/ApplicationsContests/PropellerContest/Prop128LightContoller/tabid/706/Default.aspx
  • lboucherlboucher Posts: 139
    edited 2009-01-01 01:27
    I am curious, do you actually need the zero volt detection to do dimming, or can you just do it with Pulse Width Modultion. Which as i "Think" i understand it would simply be implimented by using the pulseout command on the BS2.

    ????, why do you need zero volt detection?
  • bennettdanbennettdan Posts: 614
    edited 2009-01-01 03:06
    The PWM does not work on AC circuits just DC circuits the PWM on a DC circuit lowers the voltage of the incomming voltage with pulse witdh so the load gets a lower voltage. An AC circuit crosses zero every 8.3ms so that means its not a steady voltage so PWM is not going to lower the voltage. Dimming an AC circuit is done by waiting between 0 to 8.3ms after the ZC zero cross so the average voltage seen by the load is less. If you dont look for the ZC your PWM circuit will be erratic because of the sine wave of the AC voltage is not steady like a DC voltage.
    Look at this websight for more info.
    www.epanorama.net/documents/lights/lightdimmer.html#basics
  • lboucherlboucher Posts: 139
    edited 2009-01-01 22:37
    Alrighty i get it now. Thanks for the info!!!

    I was planning on using an SX28AC next year.

    So i will have to use one of the IO's for the zero voltage detection.

    Done a little bit of reading and see that the SX chip has 2 multifunction timers.

    This has me wondering? Will the sx chip be able to independantly dimm 16 light channels while monitoring a serial line?

    Thoughts?

    Follow up ---

    So after reading thru the help on the SX, i think i can do this by having the serial connection be "in the background" by using an interrupt to store the serial data in a ring buffer. (See the interrupt example 2nd section.)

    Can anyone confirm this? Or have you done this before? I am trying to know this will work before i go spending money again.

    I see that the serial interrupt would effect the PWM slightly, but i think that would be ok. I see the code being something like this, the main program simply watches for the zero voltage detection pin to go low, then enters a loop watching the time and for each pin if time > delay in serial data, then turn on specified channel. All the while the interrupt for the serial line brings in data whenever a pc sends the serial data. (Probably about every 20 to 40 ms)

    As a side note, i would think the BS2 to be able to do everything an SX can, but i am unable to see how the BS2 could do this, as far as i can tell it has no interrupt ability, thus it cannot do a task in the "background".

    Post Edited (lboucher) : 1/2/2009 5:54:17 AM GMT
  • dborupdborup Posts: 1
    edited 2009-01-06 20:46
    Why is the first video removed from YouTube!?
  • JamesDoughertyJamesDougherty Posts: 48
    edited 2009-01-06 21:47
    Cool project; I was hoping to see the video for this, but it says there is a copyright claim? cry.gif

    The third picture reminds me of that scene in "A Christmas Story" when he is plugging in his new lamp he won as a prize. Do you remember how that outlet looked? LOL

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    James Dougherty

    Ariel Productions
    http://www.arielproductions.com/
  • lboucherlboucher Posts: 139
    edited 2009-01-07 02:43
    Wish i knew why the video was removed, honestly don't care to take the time to follow up on it.

    I wonder if other people paid for the rights to put it on youtube, wonder how all that works.

    Ohh well. Worry about that next year.
  • JohnTJohnT Posts: 2
    edited 2009-01-07 17:19
    Here is the circuit for the Gemmy Lightshow box. It was a great buy with after Christmas sales! It only turns the AC outlets on or off. There is no dimming, though that could be changed since it uses Triacs instead of relays. I'm planning on building a MIDI controller for it, assigning each AC outlet to a specific MIDI Note ON/OFF.
  • lboucherlboucher Posts: 139
    edited 2009-12-02 18:30
    Funny parallax used a year old thread as project of the week.
    This years setup is a thousand times better.
    http://forums.parallax.com/showthread.php?p=859533

    ·
  • JohnTJohnT Posts: 2
    edited 2009-12-02 19:11
    JohnT said...
    Here is the circuit for the Gemmy Lightshow box. It was a great buy with after Christmas sales! It only turns the AC outlets on or off. There is no dimming, though that could be changed since it uses Triacs instead of relays. I'm planning on building a MIDI controller for it, assigning each AC outlet to a specific MIDI Note ON/OFF.

    I did build a Midi controller for it. Here is the circuit: http://timara.con.oberlin.edu/~jtalbert/M_AC/AC.htm
  • lboucherlboucher Posts: 139
    edited 2010-12-23 18:49
    Thought I would repost and show how far things have come.
    http://www.youtube.com/watch?v=XdTOtVXFjcA

    www.pachristmas.com
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