5 ms·

Why stop there? From scratch should involve extracting the materials from the Earth.

ss248 10y ago
I wouldn't mind actually. That toaster thing was interesting.
13of40 10y ago
You can make a razor blade diode or a pyrite diode, so I wonder if there's some way to make a make a transistor out of household junk...
- mrob 10y ago
  Jeri Ellsworth has built working transistors at home. Point contact germanium BJT: https://www.youtube.com/watch?v=vmotkjMSKnI https://www.youtube.com/watch?v=vmotkjMSKnI Etched silicon FET: https://www.youtube.com/watch?v=PdcKwOo7dmM https://www.youtube.com/watch?v=PdcKwOo7dmM The rusty razorblade + pin point contact diode doesn't need anything special because it's a Schottky diode, with a metal/N-type semiconductor junction. If you probe lots of places you can find an N-type region where the dopant is random impurities. But the transistor needs both N and P-type regions, so I don't see any way to build one with common junk. Jeri's point contact example works by diffusing phosphorus from phosphor bronze into commercially produced N-type germanium using a high current to heat it. Phosphor bronze is arguably household junk but I don't think germanium diodes are.
Dylan16807 10y ago
Because that's the point where you take things that don't compute, and make something that computes.
- tmptmp 10y ago
  >>Because that's the point where you take things that don't compute, and make something that computes. Good point but I didn't get it quite right. What is your definition of "things that compute"? I am curious.
  - Dylan16807 10y ago
    A device that can use a mathematical process to figure something out. A single transistor definitely doesn't compute. A single gate? Eh, not really. A design with a couple latches and an adder that can perform SUBLEQ? Yeah that computes if you attach a ram. A non-turing-complete pipeline of math functions? Yes, that computes, though why make that when it takes more gates than a microprocessor needs.

ss248 10y ago

I wouldn't mind actually. That toaster thing was interesting.

You can make a razor blade diode or a pyrite diode, so I wonder if there's some way to make a make a transistor out of household junk...

mrob 10y ago
Jeri Ellsworth has built working transistors at home. Point contact germanium BJT: https://www.youtube.com/watch?v=vmotkjMSKnI https://www.youtube.com/watch?v=vmotkjMSKnI Etched silicon FET: https://www.youtube.com/watch?v=PdcKwOo7dmM https://www.youtube.com/watch?v=PdcKwOo7dmM The rusty razorblade + pin point contact diode doesn't need anything special because it's a Schottky diode, with a metal/N-type semiconductor junction. If you probe lots of places you can find an N-type region where the dopant is random impurities. But the transistor needs both N and P-type regions, so I don't see any way to build one with common junk. Jeri's point contact example works by diffusing phosphorus from phosphor bronze into commercially produced N-type germanium using a high current to heat it. Phosphor bronze is arguably household junk but I don't think germanium diodes are.

Dylan16807 10y ago

Because that's the point where you take things that don't compute, and make something that computes.

tmptmp 10y ago
>>Because that's the point where you take things that don't compute, and make something that computes. Good point but I didn't get it quite right. What is your definition of "things that compute"? I am curious.
- Dylan16807 10y ago
  A device that can use a mathematical process to figure something out. A single transistor definitely doesn't compute. A single gate? Eh, not really. A design with a couple latches and an adder that can perform SUBLEQ? Yeah that computes if you attach a ram. A non-turing-complete pipeline of math functions? Yes, that computes, though why make that when it takes more gates than a microprocessor needs.