Hello everybody!
I built the following circuit on a breadboard:


The purpose of the circuit is to compare between the Reference current (49mA) in the input of the bottom ADC with the Measured current in the input of the top ADC that can be changed by using the potentiometer, actually it compares between the voltages vin(ADC1) & vin (ADC2), but the main purpose is to act as a current comparator circuit, if Measured<49mA green led should be ON and yellow OFF and if Measured>49mA yellow led should be ON and green OFF.
The circuit in Multisim works, but after I built it on a breadboard I always get constant value in the output of the U2 comparator so that always 1 led is ON and one is OFF without switching between the states even when I change the potentiometer value.
I'm using ADC0804 in my circuit and 7585 as comparators.
What can cause such problem? I need your help please!
Thanks in advance!

 

Don't the EOC pins of the ADCs need to be pulled low?
Any reason you chose this complex digital system, rather than one simple analogue comparator, to compare two currents?

 

With no indication of what is the output of the A/D converter and no indication of what the various digital lines are doing, and as we are presented with a wiring diagram not a logic schematic, it is rather difficult to guess what the problem might be.
A scheme for showing the state of the converter outputs can be just a pair of hex inverters driving LEDs. That will make diagnostics possible.

 

With no indication of what is the output of the A/D converter and no indication of what the various digital lines are doing, and as we are presented with a wiring diagram not a logic schematic, it is rather difficult to guess what the problem might be.
A scheme for showing the state of the converter outputs can be just a pair of hex inverters driving LEDs. That will make diagnostics possible.

Don't the EOC pins of the ADCs need to be pulled low?
Any reason you chose this complex digital system, rather than one simple analogue comparator, to compare two currents?

Thanks for your comments guys, the problem has been solved!
About your question Alec_t, yes, the reason is that our guide required that we use ADCs and digital comparators in our project, I used analog comparators in another circuit.

 

the problem has been solved!

What was the solution?

 

What was the solution?

Sorry for the ridiculous answer, but my project partner missed a GND connection in one of the devices, I think it was one of the ADCs.