Searching \ for '[EE] Sony laptop might have killed ICD 3' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page:
Search entire site for: 'Sony laptop might have killed ICD 3'.

Exact match. Not showing close matches.
PICList Thread
'[EE] Sony laptop might have killed ICD 3'
2008\11\12@215931 by Xiaofan Chen

face picon face
110V AC on the USB port, that is kind of dangerous.


2008\11\12@224926 by Harold Hallikainen


> 110V AC on the USB port, that is kind of dangerous.
> Xiaofan

This is very common on ungrounded power supplies. There is always capacity
between the line side and the load side of the power supply. If the
capacities are balanced, you'll find 60VAC (in the US) of common mode
voltage on the load side. If the capacity is unbalanced, you may find
something between 0VAC and 120VAC on the load side. Safety regulations
typically set a maximum on this leakage current.


FCC Rules Updated Daily at - Advertising
opportunities available!

2008\11\12@225543 by Brent Brown

picon face
On 13 Nov 2008 at 10:59, Xiaofan Chen wrote:
> 110V AC on the USB port, that is kind of dangerous.

Yes, an increasingly common problem with un-grounded switch mode power
supplies. I've come across this on notebooks and general purpose switch mode
"wallwart" type power supplies. Talked about it here some time ago.

Internally such power supplies have a small capacitor between the low voltage dc -
ve output and high voltage rectified mains -ve side of the reservoir capacitor. Low
enough in value to not exceed the 0.5 ~ 1mA ground current (body current?)
allowed by various standards, yet effective at decoupling the EMI from the high
frequency switching.

In practice this means up to 115V AC no load (with a 230V AC supply) on the low
voltage DC side with respect to ground. Dangerous? No and yes. It loads down
easily, and current under about 1mA is considered electrically safe. But it does
cause problems. It can cause visible sparking while connecting to grounded
equipment, and can sometimes be felt by the user. Leakage currents from several
interconnected appliances can also be cummulative, resulting in a potentially
dangerous current.

I don't like it. I talked to an electricity safety authority but didn't get very far with it.

Brent Brown, Electronic Design Solutions
16 English Street, St Andrews,
Hamilton 3200, New Zealand
Ph: +64 7 849 0069
Fax: +64 7 849 0071
Cell: +64 27 433 4069

2008\11\12@233123 by Bob Blick

You forgot to mention the model number, this is the new Sony Ratzapper
series laptop.

Cheerful regards,


Harold Hallikainen wrote:
{Quote hidden}

2008\11\13@000400 by apptech

> You forgot to mention the model number, this is the new Sony Ratzapper
> series laptop.

Discussion of the Ratzapper [tm] should be done using the [meece] tag.

A similar effect can be obtained using an electric blanket, where
capacitance coupling of mains can cause noticeable effects in the right


2008\11\13@063718 by cllow2020

picon face
I agree with Brent Brown, I have zap my pendrive during unplug, and about a
week or so later kill my monitor just because of intermittent UN-GROUDED UPS
power plug, in about 2 months ago.

2008\11\13@082543 by Michael Rigby-Jones

picon face

> -----Original Message-----
> From: [] On
{Quote hidden}

I get a similar problem with my iPhone.  Ever since I had it, I noticed
that if it was plugged into the charging dock, then I would get an odd
sensation if I touched the metal back of the phone.  It wasn't a shock,
but it felt exactly as though the phone was vibrating, the lighter I
touched the the phone the more pronounced it was.  Initially I wondered
if it was down to some magnetics in a switched mode supply, but the
other day I happened to have my DMM handy and measured 110v AC between
the back of the phone and ground.  I swapped the charger with the one
from my iPod just in case it was faulty and measured around the same
voltage.  It's fairly high impedance, touching the phone will pull it
down by 20-30 volts.

I also plugged in my (old, Gen 3) iPod and measured the metal back of
that and got similar results, though I never noticed the
tingling/vibrating sensation from the iPod before.

Having searched around it seems many other people have noticed this, so
I suspect this leakage is inherent to the (poor?) charger design.



This e-mail is intended for the person it is addressed to only. The
information contained in it may be confidential and/or protected by
law. If you are not the intended recipient of this message, you must
not make any use of this information, or copy or show it to any
person. Please contact us immediately to tell us that you have
received this e-mail, and return the original to us. Any use,
forwarding, printing or copying of this message is strictly prohibited.
No part of this message can be considered a request for goods or

2008\11\13@101801 by Christopher Cole

On Thu, Nov 13, 2008 at 10:59:28AM +0800, Xiaofan Chen wrote:
> 110V AC on the USB port, that is kind of dangerous.

Very dangerous to sensitive electronics.  Imagine what happens when you plug
the RJ11 of your favorite device programmer into your target circuit:  The
programmer is swinging at 150 VAC p-p, and if GND or VCC do not make contact
with the target circuit first, but instead PGC or PGD do.  I wonder if they
make RJ11 connectors with some pins longer than others to ensure ground is
met first... (like USB).  Maybe it is smartest to plug the programmer into
the target circuit first, and then plug the programmer into the notebook?

One solution is to use a grounded AC adapter, so that the DC supply has a
stable reference.  Sony offers these for free if you contact their technical


| Christopher Cole, Cole Design and Development, LLC |
| Embedded Software Development and Electronic Design |
| Stow, Ohio, USA                                                800-518-2154 |

More... (looser matching)
- Last day of these posts
- In 2008 , 2009 only
- Today
- New search...