Is this a working OR Gate? Voltage is 9V.

 

Can't you test it, yourself?

 

Hello,

Do you think that the red led will survive?

Bertus

 

Can't you test it, yourself?

Can´t test it right know, thats why i am asking....

 

Hello,

Do you think that the red led will survive?

Bertus

Oh i think i should put a resister in front of the led

 

Yes, you need a resistor in series with LED3.

You won't get much voltage out of the transistors with that connection since the voltage across the bottom resistors is only about 1.5V from the 9V battery when on, and the transistor emitter will be about 0.7V below that.

Why not just use a diode from each switch to LED3?
That will give you the OR function.

 

Yes, you need a resistor in series with LED3.

You won't get much voltage out of the transistors with that connection since the voltage across the bottom resistors is only about 1.5V from the 9V battery when on, and the transistor emitter will be about 0.7V below that.

Why not just use a diode from each switch to LED3?
That will give you the OR function.

Thank you, i haven´t thought of this..

 

What is it you are trying to do?

Is the goal to turn on an LED whenever at least one of the switches is on?

Or is the goal to understand how to make logic gates using transistors?

Or is the goal something else entirely?

What is reasonable to do depends on what it is you are trying to do.

 

What is it you are trying to do?

Is the goal to turn on an LED whenever at least one of the switches is on?

Or is the goal to understand how to make logic gates using transistors?

Or is the goal something else entirely?

What is reasonable to do depends on what it is you are trying to do.

The main goal is to turn the LED on, the second goal is to make logic gates using transistors and all logic gates should be based on a simple NAND gate.

 

The main goal is to turn the LED on, the second goal is to make logic gates using transistors and all logic gates should be based on a simple NAND gate.

Sorry, I don't see a NAND gate in your original post. Can you highlight it?

 

Is this a working OR Gate? Voltage is 9V.View attachment 170352

You already had a thread discussing an AND gate when it sounded like you wanted an OR gate.

Here's the NOR gate example I posted in that thread:
https://forum.allaboutcircuits.com/threads/and-gate-not-working-correctly.156802/#post-1356102

 

Sorry, I don't see a NAND gate in your original post. Can you highlight it?

Here's his AND gate thread.
https://forum.allaboutcircuits.com/threads/and-gate-not-working-correctly.156802/

 

Here's his AND gate thread.
https://forum.allaboutcircuits.com/threads/and-gate-not-working-correctly.156802/

Sorry, I missed that. Was looking only at this thread.

You know, "and" is series and "or" is parallel. Everything (except maybe XOR) is related to that.

 

Sorry, I don't see a NAND gate in your original post. Can you highlight it?

this is the NAND template that i try to implement in the logic gates. It does not directly have to be a NAND but you only should be able to see the basic structure

 

The main goal is to turn the LED on, the second goal is to make logic gates using transistors and all logic gates should be based on a simple NAND gate.

Then why aren't you using anything that even approaches a NAND gate?

Start with that.

 

The main goal is to turn the LED on, the second goal is to make logic gates using transistors and all logic gates should be based on a simple NAND gate.

Then why are you fiddling with OR gates?

To get an OR function from a NAND gate, you just DeMorganize the (NAND) gate.