Assuming over-riding the opto couplers to falsely confirm to the system micro that the arc is struck and the lamp is lit (maybe requiring a delay) firstly, with the lamp ps disconnected. Then I intend in the first instance to buy 5x 1.2W white LEDs, 3500K, 20 degree, for proof of concept. Assuming that sort of works then get perhaps 10 more, going down to 2700K or 3000K or perhaps (unlikely)
4000K and lenses to colimate to 2 degrees. Set inside a reversed conical silvered glass of an ex-lamp to direct spillover light into the colourwheel/light tunnel aperture. The intended LEDs are 11x10mm footprint so can be mounted quite close to the colourwheel(for 5 anyway) on a spherical back mount. I may as well retain the original fans, perhapps knocked back a bit for less noise intrusion later on.When coming to scaling up I originally was thinking of using a sectored curvi-linear silvered reflector from PIR units (with faned air cooling) but have since come across 2 degree lens converters for these LEDs so may as well go with them and shine directly from a larger spherical backing mount, directly to the colourwheel aperture.
I'd be interested in any suggestions or comments other than of the I would not bother type of replies. Anyone happen to know what the light wastage proportion is of a non-ideal paraboloid reflector and non-point source discharge lamp is? I'm aware proper LED projectors have active drives to RGB LEDs and not colour wheels but there are a lot of ink-jet-printer-syndrome surplus HD video projectors around with too expensive short-arc lamp costs to replace
Some bods been here before with converting a couple of types of discharge lamp converters
If anyone is interested, my exploration of inside a standard domestic GU10 LED lamp (to see if they were all in series or mixed series/parallel)
240V,2W. Breaking in:- hold the bulb in a glove and heat the dome cover with "low" temp hot air and prize off with a needle. With old soldering iron destroy the epoxy join between the , not obvious as silvered, pcb to the lamp housing. The slight greeen colouration is due to the reflection of the green dye of the pcb which is not glass fibre reinforced it seems, maybe epoxy substrate only. Prize the pcb away. No glass breakage at any stage. Overlay of this one marked JH-GU10-20 HV ac side 1M//0.33uF 400V dropper and 1/4W resistor size fuse/inductor/fuseable resistor? pink colour with red black brown, or reverse order, colour bands, about 0.4R to small SMD MB6S bridge rectifier. LV quasi-DC side SMD 510R dropper to 20 LEDs in series. White ceramic cap is cemented to the glass of the lamp. Bench ps 50V across LED string and 510R all LEDs just lit 54V and 0.5V over 510R and about 2.6V over each LED some sort of low level brightness. With 75% mains (240V that is) 6.5V DVM dc over 510R or 5.5V DVM ac over 510R 100% mains 9.1V "DC" or 7.2V as "AC" reading over the 510R