This is not safe. It sounds like you have some earth leakage current that would trip a modern distribution box. It sounds like your 230V is not isolated from the mains which is a dangerous thing.
But why is working well if i use my desktop pc with 750w power supply?
And i have same problem if i use laptop.
i had same problem before with old machine. Using 3 phase powerand 3 phase motor so it was same problem only that time was arduino usb electrical noice and laptop com problem.
So i replaced laptop with desktop pc and arduino and COM port are fine.Machine working without problem.
The problem is dc adapter 12v 1000mA for touch screen.
I bought touch screen from ebay without power suply. So i powered display with old dc 12v adapter.
Adapter is without earth.
Because arduino mega is connected to lenovo pc via usb, and servo driver is connected via rs232.
There is no COM noise problem.
So if is something else wrong then mega and COM will make same problem.
I will take power supply from 1 old pc and check how touch screen works with that.
Your problem is with the 230V supply, from what you describe you have wired it directly to the mains. At least you need a 1:1 isolation transformer between your mains and your wiring.
The problem is dc adapter 12v 1000mA for touch screen.
No it is not, that is class 2 equipment and dosn't need a ground. You show so little knowledge of mains equipment that you may shortly be up for a Darwin Award. At your knowlage leave you should not be plying with the stuff.
I replaced with Ac 12v adapter and there is no problem.And there is no noise going in to COM.
i tested with pc power supply and no problem.So please explain why this works?When i switch on old DC adapter same problem i got.
And hire is Servo wiring manual for 3 phase wiring and 1 phase.
i am sorry if you think I refusing. I am hire for advice.
So what happens if we don have isolation transformer and can you give me advice witch 1 will be god from
ebay?
And what is about 3 phase motors 4kw do we need for them.I sow in company some machines with 3 phase motors and i have not seen any transformer.Machines are made in Germany.
They have only circuit breakers,magnet conntactors 1 for forward and 1 for reverse,Overload Relay and that it.
Thank you for your help.And please answer for this question so i can learn something new.
And what is about 3 phase motors 4kw do we need for them.I sow in company some machines with 3 phase motors and i have not seen any transformer.
No you won't, you will also not see them connected to a laptop nor an Arduino either will you.
It is illegal to connect things to the mains without isolation, that can kill some one. With a motor directly connected to the mains their is no thing that a person can touch that could possibly be live.
That is not the case once you start to control that motor with something connected to an external circuit or laptop.
If your circuit is connected to ground and it works, then you have current flowing from the mains direct to ground. This will fail any safety standard on the planet. If for some reason the earth connector becomes disconnected then the chassis of the laptop, or any other equipment directly connected to it becomes live, exposing people to a direct electric shock. This could be fatal or cause a fire. It is not safe, do not do it.
But is it safe to turn 230v lamp using arduino and 230v arduino ralay,do we need isolation transformer in this case? with push button from arduino. I really wish to learn about safety. I will need later.
I sow on YouTube many projects wired 1 phase and without isolation transformer.
But i am glad to learn important things.
Can you attach example of isolation transformer from ebay?
But is it safe to turn 230v lamp using arduino and 230v arduino ralay
Yes.
do we need isolation transformer in this case?
No.
The isolation is provided by the relay.
Using an isolation transformer is one way of isolating a device but it is not the only way. A relay's contacts are isolated from the control circuit. The control circuit just provides a magnetic field to cause contacts to open or close.
However, relay contacts are slow and would not be suited to driving a servo. In this case, depending on what servo you have, you can isolate things by using an optical isolator. Opto-isolator - Wikipedia
Here your Arduino light up an LED and the light causes a signal on the servo's control input. Thus there is no need to connect your mains to any circuitry, they are isolated through light. This is much safer than using an isolating transformer because your control circuitry is isolated from high voltages as well as from the mains.
Post a link to the data sheet of your servo and we can see if it is suitable for isolation like this.
I will post on friday.i am not home 3 days.Instructio manual is on my pc.
I wood like to know whay servo driver dasent have isolation?And what about Nema 42 Whantai stepper driver.Is there any isolation transformer ?
I wood like to know whay servo driver dasent have isolation?
It might, you have not posted the data sheet to it so who knows? But in the absence of any evidence to the contrary you have to assum it doesn’t. Also given your problems with it then it sounds like it doesn’t.
Manufacturers can make what they want.
You normally drive stepping motors from a regulated D.C. supply, that supply will be isolated from the mains.
i am sorry if you think I refusing. I am hire for advice.