OR gate equivilant

[Dr_Doggy]

If i have two input signals will this make equivalent to OR gate output?

 

[KMoffett]

Yes. What logic family are you using...TTL?...CMOS?...? I would put a pull-down resistor on the D-input to your third F-F.

Ken

 

[ronv]

OR

In the old days we called this DTL.

 

[KMoffett]

Inverted output! Isn't that a DTL NOR gate? Reverse the diodes, delete R2, make R1 a pull-up, and you have a DTL NAND gate.

As DRL (Diode-Resistor-Logic), without the transistor, it would be an OR gate. Reverse the diodes, with a pullup resistor on the output, and you have a DRL AND gate.

Ken

 

[crutschow]

If i have two input signals will this make equivalent to OR gate output?

With a pull-down resistor it acts as an OR gate. But it will be slower than a standard OR gate so you don't want to use it if you are concerned about speed.

 

[Dr_Doggy]

how big is that resistor to be?

 

[KMoffett]

how big is that resistor to be?

What logic family gates are you using...TTL...CMOS?...?

Ken

 

[Dr_Doggy]

I dont know, I'm just talking in general, whats the difference between the two anyway> ? i hope they can get along with each other, i think im using a little of both in my circuit

 

[KMoffett]

TTL and CMOS have different input and output requirements. Can you post a schematic of what you're building?

Ken

 

[Dr_Doggy]

not really in to anything, just cause i'v gotten to know transistors and TTL now a bit, so i guess my next educational step are cmos chips