Some time ago I was introduced to the amazing world of retro slide projectors. Due to the rising cost and worsening availability of original light bulbs for these devices (especially: BA15S bayonet-mounted 220VAC 150W and 250W bulbs) an idea was raised to develop a simple retrofit solution to use modern halogen light bulbs in these projectors.
In the folder above you can find project files (Arduino code, 3D printing models) for one of the projectors (ŁZK Prexer Diaprex B11 with Rotokolor attachment).