Hi,

I would like to use two LM393 to receive 3 or 4 triggers input voltages and to operate 1 common base transistor (giving the base high or low). Meaning, when all three outputs of the opamps will be high - the transistor gate will receive high, but if one of the outputs (a or b or c or d) will be "low", than the output should be low.

Appreciate if anyone knows how to solve this or to share a schematic that solves this case?

Thank you in Advance,

Barg

 

hi barg
The LM393 is an open collector output, so if you connected a diode on each LM393, with the Cathode to the output and then connect all three Anodes together.
For the transistor Base, connect another diode, with the Cathode to the Base and the Anode to to the other 3 Anodes.
To the junction of the 3 Anodes connect a bias resistor upto the +v supply.
This will be logic AND gate.

Do you follow or would a sketch help.?
E

EDIT:
Re-looking at the circuit , we could drop diodes 1,2,3., as the LM393 is o/c

Please post a diagram of your existing circuit so that I can confirm how the LM393's need to be connected.

 

I would like to use two LM393 to receive 3 or 4 triggers input voltages and to operate 1 common base transistor (giving the base high or low). Meaning, when all three outputs of the opamps will be high - the transistor gate will receive high, but if one of the outputs (a or b or c or d) will be "low", than the output should be low.

LM393 are comparators, not opamps.

Post your schematic or a block diagram of what you want.

 

I would like to use two LM393

You could use one LM339.

 

to operate 1 common base transistor (giving the base high or low).

This is also a bit of an oxymoron. A common base transistor has it's base grounded. It seems that what the OP really meant to say was apply a high or low to the base of a common emitter transistor.

Words really matter when you're trying to describe a circuit instead of posting a schematic or block diagram. You need to use a lot of words and you need to use the correct terminology.

 

You need to use a lot of words and you need to use the correct terminology.

I would say being concise with proper punctuation is more important than being wordy.
I've seen way too any posts that are very rambling and wordy, with run-on sentences that never completely explain the problem.

 

Thank you all for your reply. I need to modify the circuit, I will post it in a new thread.