Running the XJ-A140 With Missing Diodes

[kobra000]

ok ok i didnt see it.calm down...sheesh just brainstorming here.

yes getting the wheel synchronized would be a pain..im not even sure how one would go about finding the frequency of the dlp (logic analyzer?) i figured start at the bottom with 1 rpm,then just keep going up until it achieves a happy balance im sure this can be done with a simple speed control pot wired to the transplanted color wheel...i assume with the projector on and light getting to the screen the colors would be your guide, as the RPM increases and they start looking normal,then your in the ball park. rpm kept in time with the color shift of the dlp is the only way i can think of it working.and the video i posted of the casio torn down but operating shows the phosphor wheel spinning pretty fast. also i have seen other projector with there color wheels spinning betwen 10,000 and 15,000 rpm to batch the 60 frames a second (3,600frames per minute) cycleing of other dlp chips.
=

yeah the filter was a bad idea,im sorry i didn't see your original post about it..

[krazer]

I have not gone searching for them specifically, but the DLP controller chip has R,G,B enable lines in it, designed for this purpose. If they are routed on the board it would make the diode driving trivial. If not your best bet would be a few timers derived off the color wheel, if you use a microcontroller it would only take a few lines of code to get the R,G,B enable signals derived. I think the bigger issue will be getting all of the LEDs into the DLP chip, because this will require replacing most of the optics in the projector (everything in between the red LED and the light pipe into the DLP assembly).

PS - my apologies for falling out of contact in this thread, I have been very busy with applying to grad school / keeping my grades up at UCSB

[kobra000]

hey no problem man i understand,gotta do what ya gotta do.
i have no experience with micro controllers at all.(but im willing to learn) can you suggest or recommend one?
light pipe? is that the long tunnel offset from the DLP,cause i was thinking of mounting a led as close to that as possible..basically bypassing all the other dichros and whatnot.but finding suitable LED is proved to be a total nightmare ie,this one cant be collminated,this one has too high of current,this one has the right current but very low lumen output,this one has the right NM range but cost too much....these projectors can be very disheartening!

you think if i can find another projector that uses the same type of DLP and controller chip,and a service manual to that projector.it might yield us some more hardcore data?,i know of alot of projectors that use single DLP technology. viesonic,optopma,panasonic,nec ect ect. and i have a couple of good sights that give free service manuals for them. (cant find a service manual for the xj-axx anywhere! on the net,thinking of buying that is if Keso will allow you too)

thanks Krazer,i appreciate it.


Keith

[kobra000]

Krazer

"""""""""the DLP controller chip has R,G,B enable lines in it, designed for this purpose. If they are routed on the board it would make the diode driving trivial."""""

could you elaborate on this just alittle more please? how would finding the R,G,B enable lines on the DLP controller make driving the diodes trivial? sorry but im not following.

[kobra000]

great video of the projo torn down and operating,has a link in the description to a lot of pics of its internals as well.

[kobra000]

The post "Kaeso XJ-A130 blanking..lots more data in that thread.
Krazer (sorry if i double or trippled the following,having a hard time navigating the forum host page and forgetting where im posting) BUT,i found these below and was wanting your take on them

Zener didoes http://www.ebay.com/itm/ZENER-DIODE-...-/270716795249 and was really hoping if you could tell me if they would suffice..the are a bit higher than what you suggested 4.7V 1N5337B 1 Amp 5W QTY 15 (7 dollars) now its says the following in there description

1N5337B Zener diodes, 4.7 volts, 5 watt, 1 amp for current. QTY 15. Useful for grid bias where cathode current does not exceed 1 amp""". ..does this make them better or worse?

here is the data sheet on them along with information on alot of other zener diodes as well. http://www.futurlec.com/Diodes/1N5337B.shtml only thing is it showing 2 ohms of resistance where you said 15-20 would be needed..or are zener diodes different when it comes to ohms?
thanks its appreciated

Keith.

[kobra000]

anyone got there Photolexicon ears on tonight?

[kobra000]

ok finally got some data on the current of the lasers threshold current 220ma max curent 1.7a (1700ma) max reverse current 85ma...this is good news to me. but does anyone know the voltage? i dont think it would be that high. 4.5-5 volts.

here is a datasheet for 445nm blue laser diodes that i was told best approximates the ones in the projector it gives current ratings but doesn't tell me the laser diodes forward voltage drop or operating voltage (you think that would be one of the first things a datasheet would tell you!!).....does its current data sound about right?

http://www.nichia.co.jp/specificatio.../NDB7875-E.pdf

[rhd]

ok finally got some data on the current of the lasers threshold current 220ma max curent 1.7a (1700ma) max reverse current 85ma...this is good news to me. but does anyone know the voltage? i dont think it would be that high. 4.5-5 volts.

here is a datasheet for 445nm blue laser diodes that i was told best approximates the ones in the projector it gives current ratings but doesn't tell me the laser diodes forward voltage drop or operating voltage (you think that would be one of the first things a datasheet would tell you!!).....does its current data sound about right?

http://www.nichia.co.jp/specificatio.../NDB7875-E.pdf

The Voltage is ~4.75. Depends on current. Google "445nm PIV curve" and then flip over to the images tab. That method is a pretty good shortcut to the data you need for most diodes.

[kobra000]

this thread over at LPF forums was interesting..http://laserpointerforums.com/f67/te...des-65186.html

i see alot of graphs when i switch over to images,but not exactly sure what im looking for...but i did find some interesting tidbits of info from the above mentioned thread with a nice diagram for some sort of test load,just not sure its applicable to what im doing.
but i had figured it was around 4.75 like you said.


I did something the other night.more out of sheer boredom than anything else (i was also curious if they would explode as well)..i took 24 10mm led's out of a worklight (no idea on the specs at all) and soldered them to the flexcable,hooked it up and turned the projector on..now i was certain that all the LEDs would just explode,but funny thing is ..they didnt! the projector turned them on for about 20 seconds and there was a flicker of red out of the lens,but then it shut down and started throwing the temp errors..i figure it wasn't enough load or was just under the threshold of what a proper load should be (hence why the red flicker),i had no resistor attached to the LEDs either just straight power to led..they were bright as hell! but each time i tried turning the projo on it did the same thing..flashed the LEDS for about 20 seconds and give the red flicker...yeah i know nothing truly scientific or results finding ,,but it was interesting.