Logic Gate Help Needed

I am building a Binary to Decimal converter and i need help making a flawless AND gate from bipolar-junction transistors. If someone could Send me a link or email me some schematics, I would greatly appreciate it. If you do email the schematics please make sure they are compatible with Eagle. I don't want to use a converter chip because it takes away the fun of the project for me. I have tried all of the common types of AND gate configurations using NPN's (C-fwd B-in E-collect, C-in B-fwd E-Base, Etc.).

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Easier with relays.
I don't want to use a converter chip because it takes away the fun of the project for me

Ah, but the fun of the project should be in the design too.  How many digits of binary are you decoding ? Have you drawn the K-map for it all, and eliminated unneeded states ? Exactly WHAT configurations have you tried - post circuit diagrams.
toast5678 (author)  steveastrouk5 years ago
i'm decoding 4 digits (0000-1111) i have not put the logic diagrams in my computer yet (they are in my schematics notebook) if you really need them i can get them to you. it will have to be in a few days because i got pretty banged up today when i was biking, and i dont feel like doing any work because of it.
OK. I need to see what you have tried - the links on the right "DeanGPotts" are useless BTW.

Get well soon.
toast5678 (author)  steveastrouk5 years ago
Thank you for your willingness to help, but i have found a cheap(ish) way to make AND gates. It combines an N-Channel MOSFET with an NPN Bipolar Junction. i supply power to the collecter, use base as input, and emitter is connected to drain, gate is used as the input, and source is the output.