or The ultimate Telrad / QuInsight USB Power / Blinker Mod
Every light-producing telescope sighting device for astronomy use could benefit from the so called "Blinker" feature, which helps the observer to maintain the eyes darkness adaptation as much as possible during the telescope pointing flow with that type of finders simply reducing the light exposure. That allows to point with such a device using much fainter stars than with the reticle constantly shining into observer's eyes.
I had that "blinker mod" implemented over a decade ago using the trivial LM555 timer IC for my Telrad (you can easily google for that circuit and Telrad integration guides, there are plenty online). But as I have recently acquired the more advanced collimator sight the QuInsight
I decided to make a more advanced blinker as well. But it turned out so advanced that I see it frankly opening the IoT era in amateur astronomy!