2 Input Nand Gate


Using a LED/LDR pair to form inverting Photonic logic gates. The entire Boolean logic set handled by resistors and diodes! Who'd'a thunk

Dr. CockroachDr. Cockroach 10/08/2018 at 11:265 Comments

2 Input Nand gate using only diodes and resistors.


Stefano wrote 10/25/2020 at 17:27 point

That's a pity, but I think that would be nice to measure it anyway (min, typ, max), in order to understand the real potential of the implementation.

Regarding speed would be extremely nice to have an all optical solution, meaning controlling with light if another light source pass or not, with very (very) quick reaction times. Something like this might reuse the relays computer architectures...

In any case your realization remain a masterpiece! ;)

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Ken KD5ZXG wrote 10/25/2020 at 13:41 point

How do you solder without burning and clean without staining cardboard? 

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Dr. Cockroach wrote 10/25/2020 at 14:46 point

Well, so far no burning or cleaning. The paper, card stock or cardboard seems to take the heat very well. I just have a cheap WalMart iron with a worn out tip ATM

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Stefano wrote 10/24/2020 at 23:33 point

I just discovered your diodes&light logic, it is very very interesting and the cardboard realization a masterpiece! A question: do you know the frequency limits of this type of logic?

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Dr. Cockroach wrote 10/25/2020 at 09:55 point

Not really but very slow compared to transistors as a CdS photo resistor has a noticeable reaction and recovery curve and every one seems to be different so matching them up is a bit of a pain ;-)

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