The challenge:
Control a TV or other IR device via a non-circuit based device powered by a candle for IR source. Batteries not allowed.
You can use a candle, paper, cardboard, plastic, lenses, aluminum cans etc. All hand made unpowered and rudimentary materials allowed.
You may obtain the ir message by any means including a detector, DAC, etc system. But once you have your code, those devices cannot be used.
Something I just thought of: If the slits are thin, you need a second, stationary IR blocking plate with just a slit in it that sits in front of the candle to prevent any spillover into the next or previous slit of the wheel due to the width of the candle flame.
I’d put the candle in a box with a window of the same width and height as the notches, both to keep it from spilling over and also to keep the speed of the wheel from blowing out the candle. Probably put a lens in that window too to help with apparent brightness.