My friends at Evil Mad Scientist have a new kit for sale. It’s a 555 timer circuit that you can build yourself using discrete transistors. You can wire it into all sorts of 555 timer circuits and then probe individual nodes to see how the chip actually works.The circuit board that you get with the kit has silkscreen labels that mark the functional blocks of the circuit, and silkscreened component designators that match up with the “official” Signetics schematic.
The circuit is full of interesting analog electronic design elements. You’ll be able to play with differential pairs, current mirrors, Darlington stages, diode-connected transistors, and more.
It’s a great kit if you want to learn more about how integrated circuits work, or if you’re a fan of the indefatigable 555 timer and want to have a neat conversation piece, or even if you’re just a beginning electronics hobbyist and you want to practice your electronics assembly and soldering skills.