Connecting power supply to GND

Thread Starter

josepars

Joined Nov 28, 2018
73
Hi I have grounding problem in my PCB. When I connect the negative prob of the power supply to the GND, problem is disappeared. Is there any problem if I connect the negative prob of the power supply to GND ?
 

Thread Starter

josepars

Joined Nov 28, 2018
73
What is the problem?

How is power connected to your board?
Problem is ghost touch on my touch panel but when I connect the negative probe of the 12VDC power supply to the GND there is no ghost touch. I mean will be any problem if I keep the negative prob on GND ?
 

dl324

Joined Mar 30, 2015
13,122
Problem is ghost touch on my touch panel but when I connect the negative probe of the 12VDC power supply to the GND there is no ghost touch. I mean will be any problem if I keep the negative prob on GND ?
If that's the power supply for the board, the negative terminal must be connected to the board.

Without knowing whether the power supply is isolated or how the ground on the board is connected with respect to earth ground, I can only guess at what the problem might be.
 

Thread Starter

josepars

Joined Nov 28, 2018
73
If that's the power supply for the board, the negative terminal must be connected to the board.

Without knowing whether the power supply is isolated or how the ground on the board is connected with respect to earth ground, I can only guess at what the problem might be.
Of course I connect both positive and negative probes of power supply to the board also I connected the negative probe to the GND.
 

Tonyr1084

Joined Sep 24, 2015
6,265
It would seem we're talking about some mysterious project with some unspecified issue; other than that grounding the negative lead makes the problem go away.

If you have an oscilloscope you can touch the probe tip with your finger and see some form of an AC sine wave. That's because your body is acting like an antenna and picking up ambient magnetic radiation from some electrical power line nearby. When you ground a project you drastically reduce the amount of what's called "noise". If you don't have a scope you can experience the same thing by touching the input of an audio amplifier. You will hear the 60 cycle AC hum. Put your hand near or ON a fluorescent lamp fixture the hum will get a lot louder. But if YOU are grounded then you won't get any hum because all of the received noise will be directed to ground.

A little more detail on what you have and what the issue(s) is(are) would go a long way to helping us help you.
 

BobTPH

Joined Jun 5, 2013
3,661
What is the ground on your board connected to when it is not connected to the negative of the power supply?

Bob
 
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