battery adapter

[Hobbyst46]

Wonder if the earth on the mains electricity in the apartment is not well grounded.

Yes, proper grounding and a residual-current circuit breaker (RCD, RCCB) on the main AC switches board are a must in every house. They recommend to test the RCCB once a year by pressing a button.

[Roldorf]

Hi 75RR,

Static electricity. Dry air, nylon carpet, plastic shoes. Your camera with the adapter attached could only supply a maximum of 5v x 500ma not enough to even give you a tingle. Try putting your wet tongue over the contacts of a 9v battery you will see what I mean, tastes yuck but no harm done. If you are getting tingles from other items take off your plastic sandals and see if it still happens.

[jfiresto]

The metal frames of all my PEN cameras are connected to their signal and power grounds. Presumably your battery eliminator will connect your camera's ground to the monitor's, when you plug it in. That would add more capacitance to take a static discharge.

My E-PL1's electrical buttons and dials appear to be made of or covered by non-conductive plastic. The lens release button has a metallic-looking, conductive covering. The metal hot shoe and nearly all the exterior screws are also grounded.

EDIT: Changed "flash shoe" to "hot shoe", since it also accepts an external viewfinder.

[Hobbyst46]

...

How about toaster oven discharge ?

[jfiresto]

Indeed, but I also would not exclude both static discharges and excessive 230VAC leakage, possibly from poor grounding. This may betray my upbringing, but I think we need to (cautiously) collect more data.

[75RR]

Thanks all for your suggestions. Will test the mains for ground on Monday and see where things stand then.

Shock was reminiscent of the one you get when messing about with spark plugs in an old car.



Think I have found the problem: Static Electricity! Was straightening up the nylon carpet under my office chair (there to protect the floor) and got another sharp shock when I touched my lamp.

Here is an interesting article on static electricity (surprising how high the voltage can be): https://intranet.birmingham.ac.uk/hr/do ... ricity.pdf

So all the usb battery replacement is guilty of is providing a ground, which the camera didn't have before.
.

[hans]

So all the usb battery replacement is guilty of is providing a ground, which the camera didn't have before.

Seems likely.

If you are getting tingles from other items take off your plastic sandals and see if it still happens.

Probably not a good idea when there is any question about the source of the shock. Removing insulating footwear limits static buildup but also increases the risk of electrocution if there is something wrong with the equipment or wiring.

[Roldorf]

I don't see how a 5volt USB adapter can give you a shock unless you stick your fingers in the socket that you have the USB adapter plugged into.

[75RR]

I don't see how a 5volt USB adapter can give you a shock unless you stick your fingers in the socket that you have the USB adapter plugged into.

I don't think it is. It is a conduit for the static electricity I seem to be storing up.

Did you read the pdf?

Linking here as well: https://intranet.birmingham.ac.uk/hr/do ... ricity.pdf

[Roldorf]

Hi 75RR.
Interesting reading. In the summer (like now) I always get a static shock when getting out of my car, not so in the winter. I will have to try touching the window before the door.
Edit: Nylon is one of the worst offenders for causing static electricity shocks. The old trick of rubbing you comb on your shirt and then being able to pick up pieces of paper like a magnet.

[hans]

I don't see how a 5volt USB adapter can give you a shock unless you stick your fingers in the socket that you have the USB adapter plugged into.

There could be an existing shock hazard somewhere else (in the monitor's power supply or the house wiring, for example) that was not noticed until the addition of the adapter grounded the camera. An experiment involving 75RR's hand-to-foot conductivity ("try touching it again while barefoot") is a bit dangerous unless it is absolutely certain that the shocks felt were static discharge.

[Roldorf]

I said from other items, NOT the camera. Again you cannot get a shock from a 5V USB cable, and you can not put 240 volts through a USB cable without melting it and blowing up the camera.

[hans]

I don't think anyone is suggesting 5V/500mA USB power as the source of the shock. But if there is some, as you say, "other item" now able to deliver a shock via a circuit completed by the ground connection in the newly-added USB adapter then taking your shoes off and touching things is not a safe method to figure out what is going on. The ground connection through the USB cable/adapter could easily carry lethal current without damage, if that is what is completing a circuit with some other existing shock hazard.

[Roldorf]

Hans.
I give up.

It sounds as though you are suggesting that I can get a lethal shock from getting out of my car and touching the metal of the door.
I never suggested that 75RR goes around his house touching all his electrical items to see if he gets a shock, I was simply suggesting that he may get shocks from touching grounded items when he is wearing his nylon shoes on his nylon carpet and not on items that are connected to his mains electricity especially in the warm dry weather that we currently have (prime conditions for static electricity buildup).

This whole discussion seems to me to be a rant on "Cheap Chinese Ripoffs" or a rant on Chinese products in general and I will not be posting further on this thread.

[jfiresto]

I think Hans is trying to encourage the OP to check the grounding upstream of his camera (the monitor and 230V wall outlet), as I expect it is now tied into that and because he could not identify the electrical shocks. If a fault develops in his monitor or house wiring, between high voltage and their internal grounds, and both grounds are not solidly connected to earth ground, a battery adapter cable, while doing its job, may very well pass the voltage through to the camera over the DC ground path, and make it electrically "hot". The path has more than enough metal for that. I have gotten shocked from faults in an upstream device and the house wiring, a computer assembled by a German company and a flat that was a little too quickly built after the war. The shock would not have happened if just one or the other had been faulty, but both were. Just as it was a number of otherwise tolerable problems that led to the sinking of the ship.

It would make me happy if the OP cautiously checked upstream for electrical leakage and broken grounds, because you never know. I would also encourage people to not skimp on AC to DC adapters and to buy a trusted brand.

[Chris Dee]

75RR the likely origin of this is your monitor's internal power supply. In order to achieve the voltages and switching speed needed the internal PSU has switching transformers which convert both voltage and frequency. If not properly filtered or the power supply is failing, high voltage, high frequency, current can be induced in places its not supposed to be. I'd avoid using your monitor's USB port, and think about the age/condition of your monitor.
HTH

[75RR]

75RR the likely origin of this is your monitor's internal power supply. In order to achieve the voltages and switching speed needed the internal PSU has switching transformers which convert both voltage and frequency. If not properly filtered or the power supply is failing, high voltage, high frequency, current can be induced in places its not supposed to be. I'd avoid using your monitor's USB port, and think about the age/condition of your monitor.
HTH

That is a depressing thought :(

Have not got around to checking the ground in the mains electricity, power strip and UPS yet. Will see if I can get it done on Friday.

Still think most likely culprit is static electricity (cheaper too) ... anyone know how I could confirm + measure volts?

[Hobbyst46]

75RR the likely origin of this is your monitor's internal power supply. In order to achieve the voltages and switching speed needed the internal PSU has switching transformers which convert both voltage and frequency. If not properly filtered or the power supply is failing, high voltage, high frequency, current can be induced in places its not supposed to be. I'd avoid using your monitor's USB port, and think about the age/condition of your monitor.
HTH

That is a depressing thought

Have not got around to checking the ground in the mains electricity, power strip and UPS yet. Will see if I can get it done on Friday.

Still think most likely culprit is static electricity (cheaper too) ... anyone know how I could confirm + measure volts?

AFAIK, checking home ground connections is under the mandate of professional electricians.
However, if a residual current circuit breaker (RCCB/RCD) is installed in the main fuse board of the house (where the mains counter is), pressing the small pushbutton on the RCCB should disconnect the house from power. If this happens, the RCCB is good. So the house residents are relatively safe. This test can and should be periodically done by the home owner.
Naturally this test is better done in daytime

Just a (maybe stupid) question: Is the toaster oven in the kitchen, or at any rate in a room where the floor is NOT covered with a nylon carpet ?
Note: to discharge the body from static charge, just touch a known grounded surface with the palm. A water tap (if plumbing is metal all the way down), or a large metallic object, like a fridge.

[75RR]

Just a (maybe stupid) question: Is the toaster oven in the kitchen, or at any rate in a room where the floor is NOT covered with a nylon carpet ?

I have got one of those office chairs that have wheels. They tend to mark/damage the floor so I bought a small carpet 120 x 80 cm and placed it in front of my desk - chair goes on top.

Only other culprit would be my plastic flip-flops.

Not a big fan of nylon, not a big fan of plastic in general, though on occasion it can be convenient. Perhaps I should try and replace it with yute or something similar.

[hans]

AFAIK, checking home ground connections is under the mandate of professional electricians.

Agreed, if there is still concern the shock might have been something other than simple static discharge. Using an "outlet tester" (small pod with three-prong plug, three LEDs, and a button to simulate leakage current to ground) and a multimeter (to check ground continuity of equipment) can show if something is grossly wrong, but not a substitute for a professional, of course.

... anyone know how I could confirm + measure volts?

With only a basic multimeter the results are difficult to interpret since there is almost no information about frequency spectrum or source impedance of the voltage being measured. With a typical high-input-impedance DMM it is common to measure relatively large voltages even when there is nothing wrong.

I think Hans is trying to encourage the OP to check the grounding upstream of his camera ...

I believed the discussion with Roldorf was centered around my earlier bit of counter-advice regarding troubleshooting technique, but apparently there was some misunderstanding. Since I am new here and not sure this is a good place for extended debate on electrical safety I will just restate without further justification and leave it at that:

If you have just modified an arrangement of electrical equipment, something shocks you, and you are not sure why -- do not experiment by taking your shoes off. There are situations where taking your shoes off could make the shock much worse.

[Chris Dee]

75RR the likely origin of this is your monitor's internal power supply. In order to achieve the voltages and switching speed needed the internal PSU has switching transformers which convert both voltage and frequency. If not properly filtered or the power supply is failing, high voltage, high frequency, current can be induced in places its not supposed to be. I'd avoid using your monitor's USB port, and think about the age/condition of your monitor.
HTH

That is a depressing thought

Have not got around to checking the ground in the mains electricity, power strip and UPS yet. Will see if I can get it done on Friday.

Still think most likely culprit is static electricity (cheaper too) ... anyone know how I could confirm + measure volts?

Just power the camera from a different source, if no shocks suspect the monitors internal PSU. The shock voltage is high enough to breach skin insulation, if you don't know the current potential, don't take risks.

[75RR]

.
Thanks to all!

Perhaps we can leave this thread as is until I have some new info to provide.

It is already on page 2 and no longer related to microscopy.

Thanks again to all for your suggestions and advice.