Only when will you do TO92
As through-the-hole components are being replaced by their surface-mounted equivalents, we’re starting to see the departure of the previously popular component form factors. Many metal case transistors have become a rarity years ago, while others are still hanging out albeit in fewer and fewer places. One of those is the once ubiquitous TO92 plastic transistor, which we don’t see much of at all in 2022. [Sam Ettinger] He admires the plastic D-shaped dots, And I went so far as to recreate it for a new generation to enjoy.
Although the TO92 was a relatively miniature package in its day, it is still large enough to easily fit an SOT23 or similar packaged SMD device on a small PCB. So the mini breadboard is made with enough space for the part and the three wires, and ready for packing. TO92 epoxy molding gave very poor results, so instead an SLA print was made for the T092 shell. Fits perfectly with the PCB, resulting in a perfect TO92 package. We’re sure the sheer pink packaging would have raised some eyebrows in the ’60s.
There will come a time when restorers of old electronics use and refine this technology to replace dead components. We’ve seen this technique before, after all.