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Post by harcoreta on Apr 19, 2020 5:19:16 GMT -5
Hi! I have a JVC RS46 (same model as X35), and I'm planning if it's possible a modification for bypass the ballast security control, for use an external light source. There are now high power leds (50W or 100W) and with the right optics I hope it could work, I would like to fill a 145"-150" screen. I'm using now an EPSON TW9000 with a LPE filter with good results, but I would like to use the JVC in the same room. I have a 3d printer and I can design a new lamp housing for the led and optics that can fit perfect in the projector. If the project can be done, the next step is to try to make a dynamic lighting using a programmable power Supply and an arduino, like a dynamic iris but controlling the led power. I have a friend that could help me with this. But it's secondary, only with the led mod I would be happy  The projector were not disassembled yet, according to the JVC service manual the ballast P/N is PC023411199 and looking in google alternative P/N are QAL1459-001 or MPL3120E. Is there someone with experience in modifications on JVC projectors? Any suggestions will be greatly appreciated regards! |
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Post by mastertech on Apr 19, 2020 9:55:09 GMT -5
You have the service manual for this projector?
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Post by harcoreta on Apr 19, 2020 10:57:12 GMT -5
You have the service manual for this projector? Yes, yo have a PM  |
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Post by mastertech on Apr 19, 2020 12:24:31 GMT -5
Ok, I have that already. I thought maybe you had found something better. Without a schematic or a more specific wiring diagram there is no way to help with your question. Unless one of the 2 boards(ballast or connecting board) connectors are marked as to what they are.
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Post by harcoreta on May 1, 2020 16:03:09 GMT -5
Unfortunately due to movement restrictions in my country (Spain), I cant take the projector for now, it's in my parents home.
I'm planning with a good friend to record the communication between projector and ballast board, and try to "spoof" the signal with an arduino.
I'll post and update if the project goes well, but probably it'll take a bit long.
Regards.
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Post by harcoreta on May 25, 2020 2:03:52 GMT -5
Ballast bypass done! Few days ago I could take the projector. And past weekend I disassembled the projector and connect a logic analyzer to the ballast. I was looking for a communication protocol over serial ttl that is now present on new projectors, but in this model is using discrete signals only. I did a short circuit on the optocoupler that carry the lamp status signal and It worked, the projector works perfect without a lamp, power connector on ballast was also removed. Tested with a 3W led, the luminance is too low, but enough to check that it works I've attached the possible short circuits you can do for do the bypass, on the control board or on the ballast, I did the short circuit on the optocoupler because it's easier to solder, the connectors and pins are very small. I also have done the code for do the dynamic lighting , I bought a cheap programmable power supply (DPM8608), and with the ffms2.dll plugin that works with avisynth you can log to an archive the average luminance in the scene. I did a simple script in powershell to take that information and send the desired voltaje command to the power supply. I suppose the code can be improved, I'm not a programmer, but it works very well , finally no arduino was needed, only the computer with a usb serial ttl. Possible It will be the first cheap JVC projector (not dla-Z1) with ∞:1 contrast xD Now I'm anxious waiting for the high power leds. I bought 100W and 150W and hope to be enough, next step build the new led housing Regards  |
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Post by Admin on May 26, 2020 9:42:32 GMT -5
Nice work. Thanks for sharing with us. Keep us updated on your progress.
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Post by omegasteffy on Apr 7, 2021 1:06:16 GMT -5
Really interesting project. There is a lot of defective X3/5/7 that could also benefit from such mod.
->harcoreta: Do you have any details of the optocoupler signaling? (stored scope recordings, pictures of scope etc.)
The pictures of the ballast shows a design very similar to the one in the X3/5/7.
* 5x connection
* 2x optocouplers signals toward ballast
* 1x optocoupler signals back from ballast
* similar looking green smd components (fuses?)
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Post by jayallan on Apr 26, 2021 13:36:15 GMT -5
How is it working out? Any updates? I am interested in doing a similar LED replacement |
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Post by harcoreta on Jul 4, 2021 5:44:32 GMT -5
Sorry for the delay, I have not logged into the forums for a while Really interesting project. There is a lot of defective X3/5/7 that could also benefit from such mod. ->harcoreta: Do you have any details of the optocoupler signaling? (stored scope recordings, pictures of scope etc.) The pictures of the ballast shows a design very similar to the one in the X3/5/7. * 5x connection * 2x optocouplers signals toward ballast * 1x optocoupler signals back from ballast * similar looking green smd components (fuses?) Yes I had a screenshot of the signals, If I remember the Lamp OFF/ON signal comes from the optocoupler signals back from ballast.
I have a lot of news, the modification is taking a bit complex and I did important changes. I discartered the led source rapidly, I was unable to put enough light into the projector lightpath. There are hi power leds, but it's a emitive surface, and you can't control the light, you need a small light point source, I don't knew this but it's basic optical knowledge xD Finally I move to laser... It's working progress... but yes! I could reach the same light output compared with the original lamp, and other advantages... I have doubled the projector native contrast with zoom max and iris open (worst config for contrast and max light output, typical on 20000:1 to 25000:1) I measured 50000:1, and max zoom iris -15 68000:1 (it's above manufacturer's specifications) with only a 20% of light lost compared to iris open. the answer is... with the phosphor laser source and the correct optics, the light is more controlled and have less light contamination in the projector lightpath compared with the lamp. Also, I used a custom made phosphor wheel for yellow color (green+red), I bought phosphor powder with different wavelenght, silicone, and do lot of testing. The goal was tu put into the projector the correct light temperature, for use the full working range of the panels. I'm using the high luminance mode and it's near D6500 calibrated I used some optics from casio projectors, bought two cheap defective M130 units, also used the motors, one for the custom phosphor wheel and the other is used with a frosted glass wheel to make the blue color homogeneous. For the laser source, I'm using two laser arrays, a nichia NUBM34 (for yellow color) and a Osram PLPM4L (for blue color) I have some pics but are from 2 months ago (was using two PLPM4L laser arrays), originally I used air coolers for the lasers, but now I'm installing a water cooling with an external radiator for move the heat outside the projector. Not very elegant but will be less heat inside and will be less dangerous. I'll update , probably have three or four months of work left to finish. 
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