I use 25 voltage in the PCB too, becuse the max voltage of the power source its 25 V.

 

So are you losing the voltage after R6?

 

Y

So are you losing the voltage after R6?

Yes, I dont have the PCB right now with me.

When I use 25V to power the system, in the simulation. In R10 will 5.13V .

But when I use the PCB, I measure the voltage in R10, and I have 1 V.
So start to search the problem, on the beginning. Before R6 I have 25 V after that the voltage its 16V in the output of the U3A, the voltage its is 11 V.

Somebody said that it is a problem with the impedance decoupling. But I dont know. Other person in the room said that maybe it is the protection circuit. But at 25 volts, it works.

 

Somebody said that it is a problem with the impedance decoupling.

They might just as well have said it was the flux capacitor

 

They might just as well have said it was the flux capacitor

I dont know yet.

I make some test with breadboards without using the protection circuit and I Use an T.H adaptator for the SMD Am Ops,
So when I measure the voltage in r9 and r10, the voltage was 11V . and no 18V

So I pull up the resistors and change for LM2596 DC-DC.(It doesn't work )