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Thread: Casio XJ-A 130 blanking

  1. #21
    Join Date
    May 2009


    Sorry for the confusion, of course when using silicon diodes you will need several in series, about 6 per laser removed.

    The zener isn't a bad idea, although it will probably take some experimenting to find a zener that exactly matches the laser (with many small diodes you can just add or remove a few from the string to keep the projector happy). A typical low voltage 5w zener diode will have its voltage drop specified at ~250ma, and have 2ohms of series resistance, so to extrapolate for running at 1.5A you will probably want a 4.3V zener, maybe even a few 3.3V ones if you are removing large numbers of diodes.
    something like should work well.

  2. #22
    Join Date
    Jul 2011


    First off i know this thread is on its way to the dust bin pardon me if resurrecting it irritates anyone, but it has captured my attention and i wish to know more about these zener diodes..

    i found this Zener diode calculator

    i thought it might assist us in finding a suitable diode.seems very easy to use,i personally cannot because of certain variables i do not know,ie the following Maximum input voltage,min input voltage output voltage,load current. so just take wild guess at it and usning some data Krazer told me i got these kinds of numbers.

    Maximum input voltage 32v
    minimum input voltage 3v
    output voltage 4.7v
    Load Current 1500ma

    Resitance 18.08 41.22WATTS
    Zener 4.7 7.1WATTS

    Krazer had told me in another thread that each channel is ~32 volt @~1.5-17amp so i used that.
    Do these numbers look right or wrong to anyone? if so can you explain why?

    it looks to me that the best diode to use would be a 4.7-5v 3a 15-20ohm? but in what wattage range? 5w-10w 20w? the Zener Calculator says 41.22 watts but heck i dont know thats why im asking youz guyz lol.

    i also found these: but they are only 1 amp. Krazer said that a 1 amp diode would get toasty,so i assume using heat-sinks would be a given,thing is i dont know how to marry a heatsink and a diode,unless i custom make one or perhaps glue them to the heat sink.

    when searching for 3amp diodes (as suggested here) I just keep finding only the 30-1000v 3amp rectifier diode, and im thrown off by the rectifier part (AC-DC) and since we are only using 4.5-5 volts...if something like a 40v was used since we are indeed not using 40v but only 4.5-5v @1500ma.would the difference of 35 volts play any a role or have a bearing at all? ie all more voltage than we want through,not allow enough for our needs through..burn something up?,turn our dc voltage back into AC voltage?

    i cannot find a 3amp Zener diode in the 4.5-5v range anywhere! and only have the few specs talked about here to go on(i dont know how % or,temp coefficient impacts everything so going to Digkey or Mouser is quite difficult)
    .Krazer you told me a 15-20ohm resistor would suffice,does this resistance value apply to the diodes discussed here as well? or should it be higher or lower?
    the calculator above said 18.08 ohms which i assume we could easily round off to 20ohms.
    i have no clue if these would suffice or not. if anyone has any suggestions please please post them,id appreciate the guidance.

    i also found the following but im not sure they would work cause to me they are rather odball.
    Click image for larger version. 

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    i have no idea how to implement this particular kind of diode.

    I know i ask alot of questions,and i apologize if that irks anyone,im just trying to learn is all and get my projos going.
    .any and all information or advice is greatly appreciated..again sorry if rezing this thread irks anyone.

    Last edited by kobra000; 10-25-2011 at 23:49.

  3. #23
    Join Date
    Jul 2011


    or would something like this: be more i know the specs of the diode i just listed are a total overkill.but i was more alluding to the style and physicality of the seems this type of diode would be easier to mount to a heating or sandwich in one.

    Click image for larger version. 

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