comparator without opamp? help. plz

[savage67]

i need a circuit to compare two voltage nodes.
if V1=V2, output must be 1(or 0)
else, output must be 0(or 1)

the problem is that, using a opamp is not allowed.
can you help me to solve this problem.
thanks

 

[erikl]

Here's a very simple schematic to start with.
https://www.allaboutcircuits.com/vol_6/chpt_5/16.html
The potentiometer taps are your inputs. Have fun!