how does this lift comp circuit work

It has diodes configured with op amps

I'm not sure how the circuit works and the theory behind it

 

Why do you care? What's a "lift comp"?

 

I just don't understand what those diodes do?

It rectifies the voltage it seems

 

May I ask why you are trying to learn how this entire circuit does what it is supposed to do?

 

I'm not sure what it is supposed to do, that's why i posted it to see what you guys think it is or what it does

maybe some tech might know what it is or does

 

What would you achieve by learning what it does?

 

to understand how it works , it's part of the circuit i'm troubleshooting

 

Why are you trouble shooting this circuit?

 

because the output voltage is wrong from stages after it compared to the input voltage of stages before

 

How do you know what the voltages ought to be?

 

I don't, the manual just says the input voltage of the very first stage and the output of the very last stage

So I need to know how the circuit i posted works and the theory behind it so I will know what it does

 

What manual?

 

Input is 2 vac , output is negative -.650 Vdc

 

Input is 5.80vac, output is negative -6.00vdc

 

Input is 4.00vac, output negative -2.75vdc

 

On some toher shots I saw it was a service manual for some honeywell unit.

Dexter, is your goal to repair that unit, or to learn electronics?

 

Why do you care? What's a "lift comp"?

Lift Compensation. Looks like an autopilot.

 

Yes its for an autopilot , why does it convert an ac voltage into a negative dc voltage?

 

See how it converts an AC input voltage into a negative DC voltage

Input is 2 vac , output is negative -.650 Vdc
Input is 5.80vac, output is negative -6.00vdc
Input is 4.00vac, output negative -2.75vdc

 

Dear Dexter,
If as you suggest you are working on flight electronics I would be interested to know which airlines equipment you are working on. I would make sure I never used that airline.
How anyone can allow you to "play" with such equipment with the apparent lack of knowledge of complex electronics you seem to display is beyond me.
I seriously suggest you need to undertake a comprehensive course in Electronics before being allowed to work on such vital equipment.