CHRONOSONIC COMPUCHRON SANYO LED 1975
If you are old enough to remember the good old times I bet you recall when Watchismo launched his online store in 1999. At that time there were only a few vintage timepieces to choose from including Spacemans, Bulova Sideviews, Sicura Chronographs and a bunch of ChronoSonic LEDs exactly as the one pictured. Back then I couldn't afford one for 150$ (NOS) but I was always on the look out for this model. The size and design are perfectly compromised and although the watch is goldplated I find it to be one of my favorite LEDs that I will have a difficulty to part with. Not much is known about the brand but it appears to be a sibling of CompuChron as they appear with both labels. The electronics are from Sanyo that produced a lot of high quality LED modules in those days including P4 circuitry for Pulsar.
The module is a common type with a small substrate mounted on a huge plastic carrier. If you have the skills you can easily transplant the substrate to a Pulsar as the display is the same shape and size and even angle as the P2 and P3 with the small difference of using segments instead of dots. The circuitry is placed far away from the battery wells so the most common issue with these modules is the quartz crystal that can easily be replaced. Occasionally some of the substrate components need to be checked and replaced after removing the safety enamel/film. Some attention might be focused on the solder joints between the button contacts and battery clips of which the right one with positive polarity needs to be properly connected with the case to allow the circuit to be closed upon pressing a command button (right picture below).
Keywords: chronosonic led, compuchron
Market value: 50-200$ (model, condition, box)