[reader9274]

I built one from discrete transistors in a lab class in college, on a breadboard. Fun times debugging and getting it to work. Then I flashed an led with it right next to another led flashed from a 555 chip. With the same discrete timer caps, the flashing frequencies were different due to the extra parasitics in the breadboard discrete 555 version. So had to compensate the caps to make the flashes match each other's frequency.

[jacquesm]

That's a great exercise. The hard part is always that in chips you can pull stuff that is rather tricky discretely, for instance, a multi-emitter transistor. So you can't always do a 1:1 conversion but for a 555 it is still doable.

I saw this a while ago:

https://www.instructables.com/Designing-a-555-Timer-on-Discr...

[direwolf20]

Only because odd components aren't marketable. There used to be 4-terminal MOSFETs, they weren't sold after ICs became normal. Never heard of a multi emitter transistor being sold discretely but it's possible.

[morninglight]

Real men use Unijunction Transistors like the 2N2646.

https://en.wikipedia.org/wiki/Unijunction_transistor

[buescher]

One of the books I first tried to learn from was _Miniature Projects for Electronic Hobbyists_ by one Ken W. Sessions. It was really a unijunction transistor project book. You know how some people will say you'll learn maybe not the best mental models for electronics from Forrest Mims' books? (I don't get it, they seem OK to me) Well, Forrest has nothing on Ken W. Sessions. The circuits worked, though.

[gus_massa]

Do you still have a video saved somewhere?