[Ken Shirriff]’s analysis of a fascinating high-tech paperweight created by GE at the height of the space race is as informative as it is fun to look at. This device was created to show off GE’s thin-film electronics technology, and while it’s attractive enough on its own, there’s an added feature: as soon as the paperweight is picked up, it begins emitting a satellite-like rhythmic beep. It is very well-made, and was doubtlessly an impressive novelty for its time. As usual, [Ken] dives into what exactly makes it tick, and shares important history along the way.
In the clear area of the paperweight is a thin-film circuit, accompanied by a model of an early satellite. The module implements a flip-flop, and the flat conductors connect it to some additional components inside the compartment on the left, which contains a power supply and the necessary parts to create the beeps when it is picked up.
Thin-film electronics reduced the need for individual components by depositing material onto a substrate to form things like resistors and capacitors. The resulting weight and space savings could be considerable, and close-ups of the thin film module sure look like a precursor to integrated circuits. The inside of the left compartment contains a tilt switch, a battery, a vintage earphone acting as a small speaker, and a small block of components connected to the thin-film module. This block contains two oscillators made with unijunction transistors (UJTs); one to create the beep, and one to control each beep’s duration. The construction and overall design of the device is easily recognizable, although some of the parts are now obsolete.
If you’d like a bit more detail on exactly how this device worked, including circuit diagrams and historical context, be sure to click that first link, and pay attention to the notes and references at the end. One other thing that’s clear is that functional electronics embedded in clear plastic shapes simply never go out of style.