Convert a projector in my case (Sanyo PLV-Z1) from classical lamp to LED lamp
Step 1: Replacing the Original Lamp Ballast With LED Power Source
Source for 100w led matrix and led matrix itself I ordered them from ebay.
Original lamp ballast and power source for LED are about the same size in my projector so it was relatively easy to integrate it directly into the projector box.
Connection of power supply was made directly from the switch of the lamp cover.
Step 2: Building the LED Lamp
100W LED array emits a lot of heat and therefore it must be mounted on a heat sink to dissipate the resulting heat. I initially tried mounting a radiator to fit in the designated slot without affecting the projector's lamp housing, but simply there is not enough room for a radiator able to dissipate all the resulting heat. So I actually cut the projector housing so that the cooling radiator remain outside of the box.
I have to adjust a little also the base of the radiator so it can enter into the lamp compartment. The lamp temperature sensor had to be removed.
The LED matrix is then mounted over the base of the heatsink after applying a thin layer of thermal paste. Since the mounting holes do not match led matrix, I used a small radiator on the back of the main one.
Then I attaches the optics (a plastic reflector and a lens that helps focus the light to a spot). They are on ebay also.
Then I used two textolit pads for binding the the lamp to the projector box.
Step 3: Attaching the Projector Lamp
With the two textolit plates I attached by screws in existing holes of the lamp compartiment and some new holes drilled directly into the projector lamp housing .
Step 4: Power for the Cooler Fan
I identified in the projector scheme the power for the motherboard (+ 16V) and I fed this to an fan speed control module based on a thermistor (custom made). You can find and buy such regulator for CPU fans if you don't want to build one yourself. This regulator can not fit inside my projector box so I added a small box outside over the radiator plates.
In order to fool my projector that the lamp is present I had to short pin 1 and 2 of the cable that returns from original balast. You can keep the cable from the original ballast, cut and join the two wires. This step is necessary so that the projector does not enter in lamp fail mode and close automatically. Led for lamp status remains red but it does not affect the operation.
You can get a decent picture with the new lamp of about 150cm width from a projection distance of approx. 2 m in absolute darkness. I could not test it on a projection screen but only on a white wall. On a dedicated projection screen the quality must be better. After I get one I will come back with details.
Step 5: Light Cone Reflector
After some testing I saw that much of the light was wasted in front of the focusing lens so I decided to build a reflector in the front of it. I take the mirror from an old flash light and adjusted to fit over the lens. This was not big enough to reach all the way to the optics of the projector so I build a ring from a spray can cap, cover it with aluminium foil and then fit it with adhesive over the flashlight reflector. All of this was put on top of the lens with 2 springs.
As a result the light escaping sideways from the lens was now guided inside the projector. I still have some light comming out thru the margin of the lens where the new reflector sits on top of the lens but until I get another ideea I will live with that.
Unfortunately the material of the flashlight mirror was not good enough and it was deteriorated by the heat accumulated in the glass lens that was in direct contact with it. The reflector between led and lens was unaffected (better quality). I will try to build one from aluminium so it can be cooled by the projectors fans more easily.
Step 6: Cone Reflector V.2
After the failure of previous top reflector I decided to build another to match exactly the size of condenser lens (40mm) and the opening of the first lens in projector optics (50mm). First I made the design in freecad to get an exact cone. The material used was aluminium foil from a beer can. You can use any fancy reflector material to build the cone but I wated to use something easy to find and cheap. The cone mached perfectly and gives better results than the revious one because the exact match to projector optics so less light is lost. Because we used aluminium the heat is not a problem anymore because it gets dispersed on the cone and gets cooled more easily by the projector fans.
Even after the new reflector was in place I was still not satisfied with the quantity of light the projector produce. So I was thinking that my beam from led matrix was already more uniform distributed so I do not need the whole assambly of the lens that try to make a correction to distribute a punctiform source evenly on the screen.
I was looking on the optics of this specific projector (many models have almost the same structure) and I found out that 2 integrator lens exists there and also some metal plate with spaces in it that came before the second integrator lens and a prism.
First I try to remove only the integrator lens and the metal plate. The result was more brightness but with some vertical stripes on the screen because the light that pass thru the prism was not corrected before by the metal grid.
I removed also the prism. This one is used to separate the colors in the white light before hitting the mirrors who make the actual splitting of the light. After removing that the picture gets uniform light across all surface (no shadow at the edges) and as far as I see the colors were not affected but with a lot more brightness.