Zapped by phone that is charging, only when I am grounded

[For Science!]

Hi All,

 

I'm wearing an anti-static wrist strap that's connected to my PC chassis, and this protects me and my equipment when I sit up from my chair and build up static electricity (it's a 100% guarantee shock otherwise).

However, I notice that if I pick up my phone thats charging when I am strapped up, then I receive a constant shock through the wrist band.

 

Obviously if I pick up the phone without the anti-static wrist band, all is fine and I receive no shock. Could somebody explain to me in simple terms what's going on, I am guessing this isn't suppose to be the case and that something (charger or phone) is not behaving as it should.

[mahyar]

its about charger its not properly isolated

[For Science!]

49 minutes ago, mahyar said:

its about charger its not properly isolated

I mean, it doesn’t zap me when I use it normally, so under “normal operations” it’s fine. Is this common?

[mahyar]

2 minutes ago, For Science! said:

I mean, it doesn’t zap me when I use it normally, so under “normal operations” it’s fine. Is this common?

well its long i can explain it here watch some electroboom videos on youtube and you will get it

[For Science!]

48 minutes ago, mahyar said:

well its long i can explain it here watch some electroboom videos on youtube and you will get it

I’d rather you explain here, thanks in advance.

[mahyar]

12 minutes ago, For Science! said:

I’d rather you explain here, thanks in advance.

ok 

TLDR:

your charger isn't isolated very good (but enough) when you touch it in normal situation your body will pickup electrical charge and  its voltage will also rise so the will be no current through your body because there is no where for charges to go but when you ground yourself you provide a way for those charges to go to so there will be some electrical current flowing through your body and you will feel some pain  

[greenhorn]

Hi,
does the same thing happen when you charge your phone via a USB cable that is connected to your computer? Another thing you could do is try to use another charger (ask a friend or family member for example). Are you using the charger that came with the phone?

[Lord Vile]

If the charger (or wall socket) isn't grounded then you'll get a small current that builds up on the phone, you can feel this sometimes when the phone feels like it's buzzing to you while charging. 

[greenhorn]

29 minutes ago, Lord Vile said:

If the charger (or wall socket) isn't grounded then you'll get a small current that builds up on the phone, you can feel this sometimes when the phone feels like it's buzzing to you while charging. 

That could be a reason, but all the chargers I know don't have any grounding pins. Their casing should be sufficiently isolated and the output should be isolated from the input (mains).

[For Science!]

2 hours ago, greenhorn said:

Hi,
does the same thing happen when you charge your phone via a USB cable that is connected to your computer? Another thing you could do is try to use another charger (ask a friend or family member for example). Are you using the charger that came with the phone?

its 3rd party  (RAVpower). Via PC charging it is fine though i guess its not completely an apples-to-apples comparison because lack of fast charging.

 

But I think the take home is that anti-static wrist wraps are to protect components and so grounding yourself while using live electronics is generally a bad idea.

[Lord Vile]

2 hours ago, greenhorn said:

That could be a reason, but all the chargers I know don't have any grounding pins. Their casing should be sufficiently isolated and the output should be isolated from the input (mains).

It's a thing that legitimately happens, it's harmless but an ESD strap could cause it to arc from their skin to the strap.