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Just a quick question on logic gates - in this case specifically on the diode. I've concluded for the following configurations of A and B (0,0 ; 0,1 ; 1,0) respectively \$V_{out}\$ returns 1, i.e. 5V because the circuit is open. Does the same apply for the case when both A and B have values 1 (meaning \$V_{out}\$ returns 1 too)?

diagram

I'm guessing it's the case since voltage in parallel circuits is the same and they do not sum up upon converging at the next branch.

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  • \$\begingroup\$ Stuck the image inline for you. :) \$\endgroup\$ Commented Nov 28, 2012 at 21:18
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    \$\begingroup\$ If you label your components (e.g. D1, D2, D3, D4, R1) it will be easier to explain what's going on. \$\endgroup\$
    – The Photon
    Commented Nov 28, 2012 at 21:41

2 Answers 2

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Because of the two diodes at the inputs, neither A nor B can pull the output low.

Therefore the output is always high.

Assuming the load on Vout is high-impedance, only if A or B were above 6 V or so would they have any effect on the output voltage. In that case they could pull the output above 5 V.

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enter image description here enter image description here

One of these is OR logic and the other AND. Your circuit is neither.

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