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Satyaveer Singh Rawat , 07-31-2024, 02:55 PM

Dear all please go through attached snaps whose details as follows:
P1: Schematic of PCB,
P2: Top Layer
P3: Bottom Layer
P4: Pic Without Polygon
P5: View of top layer of printed PCB
P6: View of bottom layer of printed PCB
As we can see top layer is +15 V while Bottom layer is -15 V. Problem I am facing is all the positive and negative terminal of sensors (Voltage and current both) is showing short circuit (9 Ohm on multimeter). Please help in troubleshooting. Thanks in advance.

Robert Feranec , 07-31-2024, 04:49 PM

I would start with: 9 Ohms is not a direct short circuit. Where exactly do you measure?

Satyaveer Singh Rawat , 07-31-2024, 04:57 PM

@Robert Feranec Thank you very much for your reply sir. Sir I am measuring at indicated points i.e. TS1-Pin1 and TS2-Pin1. Sir 9 Ohm is not a direct short circuit but when I am supplying +15-0-15 to the input supply of this board through DC supply (GW-INSTEK supply) it is dipping voltage from 15 V to 1.2 V instantaneously and change the Mode from Constant Voltage (CV) to Constant Current (CC) Mode.

QDrives , 07-31-2024, 08:49 PM

I cannot read all compent types. What is the LEM-....?

Mini , 07-31-2024, 09:29 PM

it is really hard to read your schematic.... make PDF output from altium then we can have a proper look

Mini , 07-31-2024, 09:32 PM

It is really hard to see, but TS1 and TS2 are top left corner in your schematic and I can tell that pin 1 isn't even connected anywhere either of them. So only way to measure any resistance between them is PCB problem or you are measuring something wrong.

Mini , 07-31-2024, 09:34 PM

Not sure why you even measuring between them if they are not connected... if you have problem with +15V and -15V then what is your resistance from +15V and -15V to GND and between them?

Mini , 07-31-2024, 09:36 PM

Maybe you mean TS1 and TS2 pin 3?

Satyaveer Singh Rawat , 08-01-2024, 07:34 AM

LEM is brand of sensors.

Satyaveer Singh Rawat , 08-01-2024, 07:39 AM

Yes it is Pin 3, Sorry I read it wrong.

Satyaveer Singh Rawat , 08-01-2024, 07:43 AM

As I mentioned the voltage dipping problem, thus I am checking the short circuit at all the points. Thus I got short circuit between those points (TS1-Pin3 and TS2-Pin3 which is connected to +15 and -15 respectively through Toggle switch.

Satyaveer Singh Rawat , 08-01-2024, 11:47 AM

Dear all thank you for your responses. I am able to debug the problem. Problem raised due to faulty voltage sensor marked with VS5 (In fig P5), which is giving 9 Ohms when measured across + and - terminals of concern voltage sensor.

QDrives , 08-01-2024, 07:39 PM

You should add thermal reliefs for you next design / itteration.

Satyaveer Singh Rawat , 08-02-2024, 10:14 AM

How to add it?

QDrives , 08-02-2024, 08:33 PM

With a rule.