Thanks for that, it is gives a better understanding of what you have, your construction looks quite good.
I am not sure how much reliance to put on all those declarations of conformity on that power supply but the big one that is missing is the UL mark. It is not surprising as it is perhaps the hardest one to obtain with respect to a power supply. UL is largely driven over concerned with the device starting fires, hence the name Underwriters Laboratory, it arose from insurers wanting to minimise their risk. I do know that UL has a much stricter limit on the earth leakage current than some of the others like CE. I am not saying go for a UL rated power supply and it will solve the problem, they are a lot more expensive and the UL rating mark might be false on Far East designs.
What it doesn't change is my guess that the problem is probably due to earth leakage and the best bet is to have things connected up before applying the power. I know this means powering down then up before making changes to things, but that is what you should do anyway. Even plugging a monitor into a computer that is running can damage things. Their are things you can plug into a computer when it is running, like USB but they have been specifically designed to be "hot swapable", these designs connect the power rails before connecting signals.
I have a similar problem with the Raspberry Pi, you can't plug many things into the GPIO pins without resetting the computer. In the case of the Pi that is a bad thing, because its main storage is an SD card, and unexpected interrupts runs the danger of destroying the card. And being Linux the boot up process is not swift.
Grumpy_Mike:
Thanks for that, it is gives a better understanding of what you have, your construction looks quite good.
I am not sure how much reliance to put on all those declarations of conformity on that power supply but the big one that is missing is the UL mark. It is not surprising as it is perhaps the hardest one to obtain with respect to a power supply. UL is largely driven over concerned with the device starting fires, hence the name Underwriters Laboratory, it arose from insurers wanting to minimise their risk. I do know that UL has a much stricter limit on the earth leakage current than some of the others like CE. I am not saying go for a UL rated power supply and it will solve the problem, they are a lot more expensive and the UL rating mark might be false on Far East designs.
What it doesn't change is my guess that the problem is probably due to earth leakage and the best bet is to have things connected up before applying the power. I know this means powering down then up before making changes to things, but that is what you should do anyway. Even plugging a monitor into a computer that is running can damage things. Their are things you can plug into a computer when it is running, like USB but they have been specifically designed to be "hot swapable", these designs connect the power rails before connecting signals.
I have a similar problem with the Raspberry Pi, you can't plug many things into the GPIO pins without resetting the computer. In the case of the Pi that is a bad thing, because its main storage is an SD card, and unexpected interrupts runs the danger of destroying the card. And being Linux the boot up process is not swift.
Thanks for the answer and the patience.
This will be my last question to not bother you.
Suppose that there is an earth leakage, how connecting things before powering up them all can be safier?
Doesn't the problem remains?
There is earth leakage in all power supplies, it just simply a matter of how much.
how connecting things before powering up them all can be safier?
Because when they are connected together before powering all the elements of the circuit are at the same potential. Then when they are powered the earth leakage currents start all at the same time so there is not a sudden change in the current. It is the sudden change in the current that causes a change in voltage which is what I think is upsetting your monitor.
You could say it is hidden in the start up process, the monitor is not yet on so you don’t see it go off. That is a bit of an over simplification but not too far from what happens.
This will be my last question to not bother you.
Don’t worry, keep asking about what you don’t understand.
Grumpy_Mike:
Don’t worry, keep asking about what you don’t understand.
Thanks for making arduino's world a better place Mike,
I really appreciate your help. In a world where internet is full of shitstorms and trolls I'm really glad to find people like you and the others here
for what it worth here the results of those circuit.
Not exactly mentioned so far, but it is generally the case that a power supply which has a ground lead on the AC cord, will also have that ground lead connected to the negative of the output. Which is why Mike is suggesting that it has something to do with the odd behaviour.
Paul__B:
Not exactly mentioned so far, but it is generally the case that a power supply which has a ground lead on the AC cord, will also have that ground lead connected to the negative of the output. Which is why Mike is suggesting that it has something to do with the odd behaviour.
You can verify that connection with a multimeter.
I'm sorry, probably I'm too noob to understand it, can you explain in different words where should I connect the multimeter?
You will almost certainly see continuity when you probe between the ground pin on the mains power input and the sleeve (negative) of the output connector.
for what it worth here the results of those circuit.
You might find this hard to believe but I have never seen an Ambilight in action before thanks.
Yes with a power supply with that much current output you are likely to have a 3 terminal mains connector. However in my experance the outputs still float rather than being connected to ground.
Grumpy_Mike:
Yes with a power supply with that much current output you are likely to have a 3 terminal mains connector. However in my experience the outputs still float rather than being connected to ground.
Which is why we want to know whether it is connected or not as part of the forensic trail.
To have the secondary not grounded, the transformers need to comply with "double insulation" standards even though it is not so marked as it has a ground pin.
Regarding the "that much current output", almost all 19 V laptop power bricks with a three pin plug do have the output grounded.
