You need to better describe the problem you are having. It's not clear to me.

 

You need to better describe the problem you are having. It's not clear to me.

Im encountering unstable analog outputs at my HMI thru RTU connection with my circuit.

Initially,surge current was present by only using one transformer into my circuit.
Then,suggested by you.ive applied two transformers into my circuit.

My project is to monitor the behaviour of the transformer thru temperature sensing under,1.no load 2.nominal load 3.overload.

Hence,findings after inserting the second transformer leads to unstable analog readings on my HMI.

Im assuming its my circuit design.probably filtering and synchronizing three sensor circuits in one.probably my DC outputs arent pure enough.
Therefore,i cant seem to know where to start.how to overcome this unstable analog readings on my HMI.

Temperature output seems ok.not a large variation.but current sensor and the voltage divider outputs varies so much.

Hope this is clear to understand,and i appreciate the attention and feedbacks.

 

I don't see any apparent problem with your circuit. Perhaps there is a ground problem. How are all the grounds connected?

Edit: In one of your previous posts showing a picture of the data acquisition circuit there appears to be a large hole in one of the chips. What is that?

 

I don't see any apparent problem with your circuit. Perhaps there is a ground problem. How are all the grounds connected?

Edit: In one of your previous posts showing a picture of the data acquisition circuit there appears to be a large hole in one of the chips. What is that?

grounds are all connected together on PCB,common ground. Attached is the PCB layout.As u can see on top of the layout are the circuit outputs. perhaps u can review the flow of the grounding by looking at the connections leading to the COMMON GROUND output at SL1 PORT2(single output).

so at my output port SL1, port1=5Vcc port2=single common ground port3=single current sensor port4=single temperature and port5=single suppy voltage reading

All this to simulate a distribution substation whereby stepdown transformer is analysed.

base on previous attachments, that was the result of high surge current coming from 230Vac into my PCB.hence, the analog board at the RTU receiving high surge ending up to explode. Therefore, linking my circuit to the RTU was restricted until i added the second transformer for isolation as u recommended.