Steering Wheels - Joysticks - Headsets - Gamepads

[xPRozACx]

Hello...

sorry for my bad english.
First: In germany we use 240V as power supply.

I measured out, on each pedal of my G25 is a voltage @ 130Vac.
I noticed as i was under my desk and i touched my case an the pedal simultanesly.

What could be the reason? Everything is working flawless.
If someone of the Logitech support crew is reading... please give me an advice what I've got to do or if Logitech will replace it.

Thanks in advance!
Stefan

Message Edited by xPRozACx on 02-10-2008 01:20 PM

[Nari]

I experienced the same problem. Though I haven't measured the exact voltage, but I felt it when I was doing some work under the table and my neck accidentally touched the pedals.

I wonder if Logitech has anything to do with this issue.

[CharlesB]

So, are you saying there is a consistent live current on your G25 pedals?

[Nari]

Hi,

I haven't checked it with a multimeter because I haven't got one at home. I cannot feel the voltage with my hands, I felt it when my neck touched both the clutch and the brake pedals. But no one was using the G25 as I was under the table that time. So yes, the voltage is always present.

Have you came across similar complaints?

Thx

[CharlesB]

Your instance was probably from static shock, and nothing more. This would be extremely likely considering the scenario of crawling underneath your desk, and the fact that it was a one time instance. The pedals can serve as a ground for static shocks.


After talking with some of the engineers, it appears the other users problem, if persisting, could be a corruption of the ground from his PC, or somehow something that puts out this voltage made contact with the pedals. We couldn't figure out how the AC adapter could generate a consistent 130V AC stream from looking at the schematics, but it's possible a poor ground inside his PC case could cause AC noise...

[Nari]

It didn't feel like shock rather than a constant sting. I think it was just the cold and sharp metal. 

I checked it with a multimeter and there is only 1-2 mV (DC) that can be measured between the ground and the pedals. Definetely more than nothing, but this not worth even mentioning as there is no way it can penatrate the human skin.

[CharlesB]

That low of a voltage would be indicative of possibly something in your PC dirtying the ground of the USB jacket in the case. The pedals have metal connection to the ground, and if there is some corruption flowing across the USB jacket, say from a poor ground in the PSU, that could cause a 1mV distortion.

[xPRozACx]

The voltage is ONLY present, when the USB cord is DISCONNECTED from the pc...
so no dirty ground of the pc cause it's not connected to the wheel!!
On my RMA G25 there's the same problem. When I plug out the USB the voltage is there.
It seems that the grounding will only be made by the pc. but it can't be ok, that i can
provocate such a voltage only by unplugging the usb!!?!

On the Cebit I spoke to the Product Manager D A CH Sven Simon.
After his holiday he'll check it for me.

[Nari]

Hi Charles,

He is right! There is about 50V (AC) voltage on my pedals. It is definetly not electric shock, but permanent potential between the pedals and any ground.

I fired up my PC, the wheel came alive and then I disconnected its USB port. I could immediately feel it on my shoulder, so I used a multimeter and here we go. It doesn't bother me really, but it is not working as designed.

(It would have been worth using grounded connectors for the G25, I think.)

Any comments?

Thx

[maze1980]

Well, the power supply is not grounded, therefore the voltage may be floating everywhere between 0 and 240V.

Devices with integrated power supplies (e.g. PCs) with metal parts that can be touched are required to connect these metal parts to ground. To mains ground, not to the mains neutral. This is expensive if there are many different metallic parts.
The G25 has many metal parts (pedals, gear stick) that can be touched. If there was an integraded power supply Logitech was forced to connect these pedals to ground. There is, however a very cheap solution to this problem: use an external power supply - like Logitech does - that delivers 24 V only. Logitech is not alone with this solution, the same is true for many power supplies for small network/USB hubs or mobibles or e.g. Dell laptops. The output voltage is typically 5 to 24V, usually DC. This voltage is ideally independed from the mains phase and neutral.

Usually the metal parts are connected to the minus pole of the power supply output.
As I understand, the the metal pedals are at least connected to the ground signal of the USB port. Is that true?
Or are the pedals connected to the minus pole of the power supply output?

Maybe: Do you use a low-quality USB hub that might be the source of the 50V?