Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

(dont ask how much they are).

Well if they were dangerous, they should come with a warning, but if they
start blowing up phones, even at the price you would probably have a claim
against the shop if there was no warning.
Brian

--
From the Bed of Brian Gaff.
The email is valid as
Blind user.
"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned
lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

(dont ask how much they are).

"Brian Gaff" wrote in message
...
Well if they were dangerous, they should come with a warning, but if they
start blowing up phones, even at the price you would probably have a claim
against the shop if there was no warning.
Brian

So far I've cracked open a £3.99 one from Lidl and another from Poundland,
neither looked conspicuously dodgy, but 12V down to 5V involves a buck
regulator that has a (switching) series pass transistor - if that fails
short circuit, the 12V will pass through like a dose of salts!

If the application is life support critical, any risk can be eliminated by a
thyristor "crowbar" failsafe circuit. Easy enough to splice a breakout box
into the lead or with a bit of manual dexterity could be squeezed into the
existing case.

Home Bargains have a cigarette adaptor for £1.49, but it only has a white
thin-wide connector - probably for ipad or something.

If you want a failsafe 12V to 5V converter; start with a buck converter that
produces 3.3V - then use a flyback converter to boost it back up to 5V.

If the flyback transistor fails; it shorts the output and produces no
voltage out - just in case the preceeding buck fails, its dead easy to rig
the flyback section to latch up on overvoltage, also producing no output.

On Fri, 16 May 2014 16:34:32 +0100, "Ian Field"
wrote:



"Brian Gaff" wrote in message
...
Well if they were dangerous, they should come with a warning, but if they
start blowing up phones, even at the price you would probably have a claim
against the shop if there was no warning.
Brian

So far I've cracked open a £3.99 one from Lidl and another from Poundland,
neither looked conspicuously dodgy, but 12V down to 5V involves a buck
regulator that has a (switching) series pass transistor - if that fails
short circuit, the 12V will pass through like a dose of salts!

If the application is life support critical, any risk can be eliminated by a
thyristor "crowbar" failsafe circuit. Easy enough to splice a breakout box
into the lead or with a bit of manual dexterity could be squeezed into the
existing case.

Home Bargains have a cigarette adaptor for £1.49, but it only has a white
thin-wide connector - probably for ipad or something.

If you want a failsafe 12V to 5V converter; start with a buck converter that
produces 3.3V - then use a flyback converter to boost it back up to 5V.

If the flyback transistor fails; it shorts the output and produces no
voltage out - just in case the preceeding buck fails, its dead easy to rig
the flyback section to latch up on overvoltage, also producing no output.

The optimum way to guard against such a risk is to use a transformer
to magnetically couple the pulses. The final coupe de grace fat pulse
from the shorted transistor will only generate a few dozen extra
millivolts worth of surge at most, followed by a rapid decay of
voltage, followed a few milliseconds later by the safety fuse blowing.
--
Regards, J B Good

"Johny B Good" wrote in message
...
On Fri, 16 May 2014 16:34:32 +0100, "Ian Field"
wrote:



"Brian Gaff" wrote in message
...
Well if they were dangerous, they should come with a warning, but if
they
start blowing up phones, even at the price you would probably have a
claim
against the shop if there was no warning.
Brian

So far I've cracked open a £3.99 one from Lidl and another from Poundland,
neither looked conspicuously dodgy, but 12V down to 5V involves a buck
regulator that has a (switching) series pass transistor - if that fails
short circuit, the 12V will pass through like a dose of salts!

If the application is life support critical, any risk can be eliminated by
a
thyristor "crowbar" failsafe circuit. Easy enough to splice a breakout box
into the lead or with a bit of manual dexterity could be squeezed into the
existing case.

Home Bargains have a cigarette adaptor for £1.49, but it only has a white
thin-wide connector - probably for ipad or something.

If you want a failsafe 12V to 5V converter; start with a buck converter
that
produces 3.3V - then use a flyback converter to boost it back up to 5V.

If the flyback transistor fails; it shorts the output and produces no
voltage out - just in case the preceeding buck fails, its dead easy to rig
the flyback section to latch up on overvoltage, also producing no output.

The optimum way to guard against such a risk is to use a transformer
to magnetically couple the pulses. The final coupe de grace fat pulse
from the shorted transistor will only generate a few dozen extra
millivolts worth of surge at most, followed by a rapid decay of
voltage, followed a few milliseconds later by the safety fuse blowing.

I agree with that - but you're not going to get a transformer at those
prices.

P Jameson wrote:

Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

USB ports on laptops generally only provide 0.5A, divide that 0.5A
between five devices and it wouldn't go far, so presumably it has five
different types of connector and you pick the one that fits the phone?

Modern phones will take up to 1 or 2A, so charging will be slow, some
phones won't stoop that low and will refuse to charge at all.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

Provided the phone wants 5V (which is what USB provides) the supply is
regulated for the innards of the laptop anyway.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

No, it'll be regulated from the car's nominal 12v down to 5V.

On Monday, May 5, 2014 3:59:14 PM UTC+1, P Jameson wrote:
Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

The laptop would be damaged by voltage spikes too - so yes.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

I doubt it, but this is *slightly* more dodgy. It depends on your car
electrics. High quality adaptors would have plenty of smoothing to remove
any spikes.

(dont ask how much they are).
.... but you probably don't get high quality for £1

"Martin Bonner" wrote in message
...
On Monday, May 5, 2014 3:59:14 PM UTC+1, P Jameson wrote:
Poundland are doing a little cable with USB at one end and five
connections
the other end to connect to a variety of different Smart Phones. So you
can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

The laptop would be damaged by voltage spikes too - so yes.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned
lead.

Would the cigarette socket also be likely to 'spike' and damage the
phone?

I doubt it, but this is *slightly* more dodgy. It depends on your car
electrics. High quality adaptors would have plenty of smoothing to remove
any spikes.

i had a cheap garmin usb car charger let it's magic smoke out once.... the
second day of use in my new car (both the charger and the car)
Not a nice thing to happen as your driving, luckily we were in town, but got
some funny looks when a smoking charger was chucked out the window into the
gutter,

i then got one of those tomtom branded fag lighter extensions with 2 usb
sockets on the side, one usb socket is a 1 or 1.5 amp 'fast charge' socket,
and it allows me to plug in the charger for the brodit phone mount due to
the fag lighter socket pass through.

but for those cable jobbies with a USB A socket on one end, and a selection
of mini, micro and those awkward ******* phones that still use proprietry
charging jacks, they usually have no electronics in them at all, so it'll be
upto the devise providing the power to keep to the usb voltage and current
standard,

On 05/05/2014 16:15, Martin Bonner wrote:

High quality adaptors would have plenty of smoothing to remove
any spikes.


They probably do not. Some of the "quality" branded 12V/5V adapters for
the car are so small there is no room for anything large.

It will be a switched mode converter using a commonly available chip
that cost pence.

As already stated the current available from a USB lead connected to a
computer/laptop will be limited and the capability will be charging one
phone at a time. Even from a 12V/5V converter for the car probably it
will be limited to charging only one or two devices at the same time.


--
mailto:news{at}admac(dot}myzen{dot}co{dot}uk

P Jameson scribbled...


Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

(dont ask how much they are).


There's not enough power for them to work on many laptops. I've had one
connected to my pc for a couple of years, never had a problem with it.

On Monday, May 5, 2014 3:59:14 PM UTC+1, P Jameson wrote:

Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.
Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

never a problem

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.
Would the cigarette socket also be likely to 'spike' and damage the phone?
(dont ask how much they are).

this is less certain. There are electronics out there that dont survive or protect against the transients that are sommomnish in vehicles. I've no idea about poundland's specs.


NT

"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned
lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

(dont ask how much they are).

The multi-connector is just a splitter - if you get any spikes, they're
coming from the laptop.

The specification is pretty tight: 5V @ 500mA - reasonable to assume you can
only charge one gadget ar a time.

The car adaptor obviously has some kind of voltage regulator to drop the 12V
down to 5V - at £1 you can afford to break one open and describe to us
what's in it so we can give better informed advice about any potential risk.

In article ,
"Ian Field" writes:

The car adaptor obviously has some kind of voltage regulator to drop the 12V
down to 5V - at £1 you can afford to break one open and describe to us
what's in it so we can give better informed advice about any potential risk.

I've broken many open, to pinch the small switched mode PSU out of them
to use for something else. I've never seen one with any protection against
the FET shorting (which would generate 12V output), but I've never had that
happen yet either.

You can get ones which supply 4.2A now, for 2 x 2.1A USB outputs.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...
In article ,
"Ian Field" writes:

The car adaptor obviously has some kind of voltage regulator to drop the
12V
down to 5V - at £1 you can afford to break one open and describe to us
what's in it so we can give better informed advice about any potential
risk.

I've broken many open, to pinch the small switched mode PSU out of them
to use for something else. I've never seen one with any protection against
the FET shorting (which would generate 12V output), but I've never had
that
happen yet either.

You can get ones which supply 4.2A now, for 2 x 2.1A USB outputs.

Having missed out at Poundland, I went in Lidl and this weeks weekly offers
include a £3.99 cig-socket adapter with generous assortment of pluggable
phone charging connectors.

Curiosity overcame my tight fisted ness - I'll crack it open later to see
what's in it.

On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"
wrote:

Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

I have no personal experience of this, however....

Charging a Smartphone from a USB socket on a PC or Mac is completely
normal. There should be no voltage spikes as the power output from the
USB socket is designed to power external devices. The real question here
is whether a single USB socket can supply enough current to charge five
Smartphones at once in a reasonable time.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

The cigarette lighter socket plug on the connector for charging my
non-smart Nokia mobile has on the label:

Inoput: DC 12V/24V
Output: 5.7V 800 mA

The mains adpater for charging that phone has an output of 5.3V DC.

--
Peter Duncanson
(in uk.tech.digital-tv)

"Peter Duncanson" wrote in message
...
On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"
wrote:

Poundland are doing a little cable with USB at one end and five
connections
the other end to connect to a variety of different Smart Phones. So you
can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

I have no personal experience of this, however....

Charging a Smartphone from a USB socket on a PC or Mac is completely
normal. There should be no voltage spikes as the power output from the
USB socket is designed to power external devices. The real question here
is whether a single USB socket can supply enough current to charge five
Smartphones at once in a reasonable time.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned
lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

I think the point is whether a £1 charge adapter is safe to use on say; a
£100 smartphone for instance.

If it uses a series pass transistor in the regulator, there's always a
possibility the transistor could fail short-circuit and dump the full 12V on
the USB connector.

If the target device uses a lithium battery, a fault condition of 12V on the
USB connector could overwhelm the charge control chip and cause
overcharging - overcharged lithium cells tend to get thermal runaway and
vent with flaming gas!

How many corners did they cut to get it on the shelves at that price?!

In article , Ian Field
wrote:


"Peter Duncanson" wrote in message
...
On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"


No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

I think the point is whether a £1 charge adapter is safe to use on say;
a £100 smartphone for instance.

If it uses a series pass transistor in the regulator, there's always a
possibility the transistor could fail short-circuit and dump the full
12V on the USB connector.

How many corners did they cut to get it on the shelves at that price?!

The discussion and low price bring to mind something I discovered years ago
in kit supplied by someone.

The kit required various 12V / 9V / 5V supplies for different items in the
box. The 'designer' sic supplied some of the 9V or 5V by adding series
resistors to the output from a 12V regulator.

The result was predictable. The voltages varied as the items drew currents
that weren't constant. Performance was awful. And in the end some of the -
very costly - items failed due to drawing a 'lower than assumed' current,
so experiencing high rail voltages.

Caveat emptor. 8-/

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

Jim Lesurf wrote:

The kit required various 12V / 9V / 5V supplies for different items
in the box. The 'designer' sic supplied some of the 9V or 5V by
adding series resistors to the output from a 12V regulator.

That is absolutely appalling!

--
SteveT

"Steve Thackery" wrote in message
...
Jim Lesurf wrote:

The kit required various 12V / 9V / 5V supplies for different items
in the box. The 'designer' sic supplied some of the 9V or 5V by
adding series resistors to the output from a 12V regulator.

That is absolutely appalling!

Many moons ago I bought a PSU 'kit' to supply 6v to the motor of a portable
tape recorder. It was advertised as supplying 6V, 9V or 12V at up to 1A. It
consisted of a 12V output transformer, a rectifier, a 12V Zener, a
multi-tapped dropper resister and some capacitors for smoothing.

It would really only supply 1A at 12V; the use of the dropper resistor meant
that it couldn't supply any other voltage with reasonable regulation - even
a tranny with a push-pull output wouldn't have worked.

--
Max Demian

In article , Steve
Thackery
wrote:
Jim Lesurf wrote:

The kit required various 12V / 9V / 5V supplies for different items in
the box. The 'designer' sic supplied some of the 9V or 5V by adding
series resistors to the output from a 12V regulator.

That is absolutely appalling!

Yes. We had to spend about two-three months going though what had been
done and redesigning/rebuilding the kit. It was also plauged with RF loops,
leaks, etc.

By the time this all came to light the originator had changed job and
employer. Heaven knows what happened next!

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

"Jim Lesurf" wrote in message
...
In article , Ian Field
wrote:


"Peter Duncanson" wrote in message
...
On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"


No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

I think the point is whether a £1 charge adapter is safe to use on say;
a £100 smartphone for instance.

If it uses a series pass transistor in the regulator, there's always a
possibility the transistor could fail short-circuit and dump the full
12V on the USB connector.

How many corners did they cut to get it on the shelves at that price?!

The discussion and low price bring to mind something I discovered years
ago
in kit supplied by someone.

The kit required various 12V / 9V / 5V supplies for different items in the
box. The 'designer' sic supplied some of the 9V or 5V by adding series
resistors to the output from a 12V regulator.

The result was predictable. The voltages varied as the items drew currents
that weren't constant. Performance was awful. And in the end some of the -
very costly - items failed due to drawing a 'lower than assumed' current,
so experiencing high rail voltages.

Caveat emptor. 8-/

These days, a large order of a popular SMPSU chip works out cheaper per part
than a row of fat power dropper resistors.

They can make the case a lot cheaper too, if there's not a lot of heat
generated.

On Wed, 7 May 2014 16:56:18 +0100, "Ian Field"
wrote:



"Jim Lesurf" wrote in message
...
In article , Ian Field
wrote:


"Peter Duncanson" wrote in message
...
On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"


No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

I think the point is whether a £1 charge adapter is safe to use on say;
a £100 smartphone for instance.

If it uses a series pass transistor in the regulator, there's always a
possibility the transistor could fail short-circuit and dump the full
12V on the USB connector.

How many corners did they cut to get it on the shelves at that price?!

The discussion and low price bring to mind something I discovered years
ago
in kit supplied by someone.

The kit required various 12V / 9V / 5V supplies for different items in the
box. The 'designer' sic supplied some of the 9V or 5V by adding series
resistors to the output from a 12V regulator.

The result was predictable. The voltages varied as the items drew currents
that weren't constant. Performance was awful. And in the end some of the -
very costly - items failed due to drawing a 'lower than assumed' current,
so experiencing high rail voltages.

Caveat emptor. 8-/

These days, a large order of a popular SMPSU chip works out cheaper per part
than a row of fat power dropper resistors.

They can make the case a lot cheaper too, if there's not a lot of heat
generated.

That's been the prime reason for using switching regulators in small
wallwart powered devices (ethernet switches, routers etc) for over a
decade now.

For once, a cost cutting measure that offers the end customer an even
greater benefit in that you can replace a faulty wallwart[1] with any
6 to 15 volt DC wallwart with a matching or greater VA rating with
impunity as long as the plug matches the socket.

If the plug doesn't match you can just cut the plug off the end of
the old wallwart and graft it onto the end of the replacement
walwart's lead (or, better still if you know how to use a toffee
hammer and a hot glue gun, swap the complete lead over to the new
wallwart).

This is an exercise I've done many times, usually to replace an
inefficient wallwart with a more efficient one to save a watt or two
on a 4 to 6 watt load. It's not a lot by itself but the savings can
mount up on a bunch of such kit that's typically running 24/7 year in
year out.

[1] Even the cheaper ac output transformer types can usually be
replaced by a DC output wallwart on account the input circuit of the
switching regulator has a fullwave bridge rectifier with a 16 or 25v
rated smoothing cap through which the DC from the wallwart will be
passed at the expense of about a 1.5 volt drop in the rectifier
bridge.

6 volts might not be quite enough in this case. A 7.5v minimum up to
a maximum of 15v should still be ok (and if the input cap has a 25v
rating, you can use even higher output voltages right up to 25v - no
artificial voltage veto as per the same circuitry typically used by
laptop makers).
--
Regards, J B Good

On Mon, 05 May 2014 17:50:22 +0100, Peter Duncanson
wrote:

On Mon, 5 May 2014 15:59:14 +0100, "P Jameson"
wrote:

Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

I have no personal experience of this, however....

Charging a Smartphone from a USB socket on a PC or Mac is completely
normal. There should be no voltage spikes as the power output from the
USB socket is designed to power external devices. The real question here
is whether a single USB socket can supply enough current to charge five
Smartphones at once in a reasonable time.

I suspect that is not its intended purpose. As another poster has
commented, it is more likely to be designed to allow connectivity with
different devices.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

No. The adapter will contain electronics to reduce the voltage to what
is needed by the phone and will regulate it.

I'm sure that's true but I think the point of the question is whether
a device that costs £1 will be up to the job.

On 05/05/2014 15:59, P Jameson wrote:
Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

It's only a dumb cable - the voltage comes from the laptop. The laptop's
USB output should be regulated to 5v - so it won't damage the phone.
Just mightn't charge it as fast as a dedicated charger 'cos the laptop's
USB will likely only supply 500mA.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?


No, it will be a regulated DC to DC converter to produce 5v from the
car's 12+ volts. Very likely the same innards as those sold by the likes
of Maplin at several times the price.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Mon, 05 May 2014 17:52:43 +0100, Roger Mills
wrote:

[snip]

No, it will be a regulated DC to DC converter to produce 5v from the
car's 12+ volts. Very likely the same innards as those sold by the likes
of Maplin at several times the price.

I think you have analysed the question correctly but not extended this
analysis into your answer :-)

"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

CBA buying another one to investigate further.

--

Graham.

%Profound_observation%

On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.
--
Regards, J B Good

On Tue, 06 May 2014 00:23:03 +0100, Johny B Good
wrote:

On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.

Now you tell me! ;-)



--

Graham.

%Profound_observation%

On Tue, 06 May 2014 16:17:51 +0100, Graham. wrote:

On Tue, 06 May 2014 00:23:03 +0100, Johny B Good
wrote:

On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.

Now you tell me! ;-)

Like you, I was non the wiser as to it being a flash memory to USB
pen drive converter when I bought it and assumed it was a card reader
where you can leave it plugged into the USB port and eject and insert
the media as per a card reader.

It took me a few tries before I was convinced it was simply a pen
drive where you could pre-load the flash memory card of your choice.

I think it was the parkable USB plug on a very short cable that had
confused me. The earlier version which just looked like an oversized
pen drive with an SD slot left no such room for confusion.
--
Regards, J B Good

"Johny B Good" wrote in message
...
On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.

I've bought multi-card readers from various suppliers and paid considerably
more than £1 for them - without exception, any camera has refused to
recognise a card formatted by one of these card readers.

On 06/05/2014 17:08, Ian Field wrote:


"Johny B Good" wrote in message
...
On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.

Although you probably could eject the media from systray and then remove
the card it would be more fiddly to do so.

I've bought multi-card readers from various suppliers and paid
considerably more than £1 for them - without exception, any camera has
refused to recognise a card formatted by one of these card readers.

That is more than likely due to Windows perverse default formatting
strategy being inconsistent with what the camera expects to see. Most
cameras require that a certain directory structure is present on their
formatted media and some are very fussy about the file system.

I had a nasty fault with my Pentax istD when new sD memory cards crossed
the 2GB to 4GB barrier. The camera formatted it OK recognised there was
space on the card and allowed continued shooting after the 2GB barrier
but failed to store any of them. A firmware update fixed it.


--
Regards,
Martin Brown

On 06/05/2014 17:08, Ian Field wrote:


"Johny B Good" wrote in message
...
On Mon, 05 May 2014 18:35:03 +0100, Graham. wrote:

On Mon, 5 May 2014 19:11:19 +0200, "tim....."
wrote:



"P Jameson" wrote in message
...
Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

I bought a poundland (actually it was a 99p shop) USB hub

it was CFU

tim


I bought a USB SD card reader from Pound World but it failed after a
few weeks. I bought another one but that failed too.
I think if you plug and unplug the whole thing from the computer it is
OK but it doesn't like the card being inserted or removed when the
reader is powered.

That's not a card reader, it's a flash to USB pen drive converter.
The idea is that you load an appropriate memory card into the slot
then plug it in. When it comes to ejecting it, you have to treat the
whole thing the same as you would a usb pen drive, that is, you use
the 'safely eject hardware' applet in the systray before unplugging it
from the USB slot.

I've bought multi-card readers from various suppliers and paid
considerably more than £1 for them - without exception, any camera has
refused to recognise a card formatted by one of these card readers.

That's because, while they are formatted in camera using FAT32 or ExFAT,
the cameras also want to see certain directories that they put on the
card while formatting it for use. Every camera type has a different name
for these directories, and a card formatted in a Fuji will not be
recognised as formatted by a Sony, and vice versa, although after a card
is formatted by both cameras, it will work equally well in both cameras,
as it has both sets of proprietary directories, and all the camera does
when formatting is check the FAT and add its oewn directories. The
exception is, IIRC, Canon, who use a non-standard SD format instead of
FAT, which makes their cards unreadable except by their software, even
out of the camera.

My JVC HD video camcorder puts about five directories on the card, and
it uses them for storing things like scratch files and metadata.

--
Tciao for Now!

John.

On 05/05/14 15:59, P Jameson wrote:
Poundland are doing a little cable with USB at one end and five connections
the other end to connect to a variety of different Smart Phones. So you can
charge your phone from your laptop.


Had a look a couple of weeks ago, they also sell USB phone chargers that
plug into the mains. Of course these are safe. Only a quid.



So I spent a while in the shop thinking I'd buy one to take to bits out
of morbid curiosity, but then I spotted a bag of 'spicy crackers' that
probably rates higher in the morbidity for a pound sweepstake. So I
bought that...



Hmmm, WiFi doesn't permeate too well here 6 feet down. Am I getting out?


--
Not Me

"Adrian C" wrote in message
...
On 05/05/14 15:59, P Jameson wrote:
Poundland are doing a little cable with USB at one end and five
connections
the other end to connect to a variety of different Smart Phones. So you
can
charge your phone from your laptop.


Had a look a couple of weeks ago, they also sell USB phone chargers that
plug into the mains. Of course these are safe. Only a quid.



So I spent a while in the shop thinking I'd buy one to take to bits out of
morbid curiosity,

There's various gadgets in Poundland that I'd like to pull apart out of
curiosity - but all those £'s mount up.

P Jameson wrote

Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

Yes. The voltage is determined by the laptop, not that cable thing.

The very fundamental problem tho is that there are a variety of
ways those things signal how much current they need so its not
very likely that an el cheapo cable thing will be able to do that
correctly with all the phone connectors, so it wont necessarily
charge the phone as quickly as possible, or at all in the worst cases.

They also do an adapter to plug into the car cigarette socket with a USB
femail socket built in. This will then accomodate the first mentioned
lead.

Would the cigarette socket also be likely to 'spike' and damage the phone?

That’s certainly much more likely.

(dont ask how much they are).

"Rod Speed" wrote in message
...
P Jameson wrote

Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone with
'spikes' ?

Yes. The voltage is determined by the laptop, not that cable thing.

The very fundamental problem tho is that there are a variety of
ways those things signal how much current they need

In the original USB specification it was 100mA unless the target device
signalled otherwise, then a max 500mA was available.

AFAIK that has largely been dropped and the full 500mA is usually available
by default.

A common scheme is "Polyfuse" protection - its a PTC thermistor that can
heat up with the current flowing through it, at a certain current it heats
enough to increase in resistance enough to practically stop current flow.

When the overload is removed it cools and returns to low resistance, so its
self resetting.

In article , Ian Field
wrote:


"Rod Speed" wrote in message
...
P Jameson wrote

Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone
with 'spikes' ?

Yes. The voltage is determined by the laptop, not that cable thing.

The very fundamental problem tho is that there are a variety of ways
those things signal how much current they need

In the original USB specification it was 100mA unless the target device
signalled otherwise, then a max 500mA was available.

AFAIK that has largely been dropped and the full 500mA is usually
available by default.

A common scheme is "Polyfuse" protection - its a PTC thermistor that can
heat up with the current flowing through it, at a certain current it
heats enough to increase in resistance enough to practically stop
current flow.

When the overload is removed it cools and returns to low resistance, so
its self resetting.

That could well explain why my "Nokia Smart Phone" refused to charge from a
cheap car USB adaptor.

--
From KT24

Using a RISC OS computer running v5.18

"charles" wrote in message
...
In article , Ian Field
wrote:


"Rod Speed" wrote in message
...
P Jameson wrote

Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone
with 'spikes' ?

Yes. The voltage is determined by the laptop, not that cable thing.

The very fundamental problem tho is that there are a variety of ways
those things signal how much current they need

In the original USB specification it was 100mA unless the target device
signalled otherwise, then a max 500mA was available.

AFAIK that has largely been dropped and the full 500mA is usually
available by default.

A common scheme is "Polyfuse" protection - its a PTC thermistor that can
heat up with the current flowing through it, at a certain current it
heats enough to increase in resistance enough to practically stop
current flow.

When the overload is removed it cools and returns to low resistance, so
its self resetting.

That could well explain why my "Nokia Smart Phone" refused to charge from
a
cheap car USB adaptor.

In any computer, the 5V rail the USB supply comes from is capable of at
least several amps, without short circuit protection, a mishap could result
in melted copper tracks on the motherboard.

The arrangement in a car adapter is a little different - and there's various
ways of going about it depending how cheap they want to make it.

Possibly the best way is with a switch-mode chip like the industry standard
MC34063 - whether you'll get that for a £ is another matter.

Next time I go into town, I might punt a £ for one just to break open and
see what's in it.

On Mon, 5 May 2014 21:07:39 +0100, "Ian Field"
wrote:



"charles" wrote in message
. ..
In article , Ian Field
wrote:


"Rod Speed" wrote in message
...
P Jameson wrote

Poundland are doing a little cable with USB at one end and five
connections the other end to connect to a variety of different Smart
Phones. So you can charge your phone from your laptop.

Would the voltage likely be *steady* enough not to damage the phone
with 'spikes' ?

Yes. The voltage is determined by the laptop, not that cable thing.

The very fundamental problem tho is that there are a variety of ways
those things signal how much current they need

In the original USB specification it was 100mA unless the target device
signalled otherwise, then a max 500mA was available.

AFAIK that has largely been dropped and the full 500mA is usually
available by default.

A common scheme is "Polyfuse" protection - its a PTC thermistor that can
heat up with the current flowing through it, at a certain current it
heats enough to increase in resistance enough to practically stop
current flow.

When the overload is removed it cools and returns to low resistance, so
its self resetting.

That could well explain why my "Nokia Smart Phone" refused to charge from
a
cheap car USB adaptor.

In any computer, the 5V rail the USB supply comes from is capable of at
least several amps, without short circuit protection, a mishap could result
in melted copper tracks on the motherboard.

Not just any computer MoBo, only PC Chips MoBos ime. Even here they
do add a safety fuse in the form of either a very thin circuit trace
or an smd inductor, not items you'd normally class as a fuse but, at 5
volts, good enough to stop a conflagration.

However, the downside of this one shot fusing protection is that all
the USB and PS/2 sockets lose their 5v rail (keyboard and mouse stop
working). I should know 'cos I've bridged a few burnt out
inductors/cct traces with a 3 amp polyfuse on these ****e MoBos (after
clearing the short cicrcuit, usually a vandalisedd USB socket from
which I've snipped the offending pin).

With every other brand of MoBo I've seen, the standard practice is to
completely forego the USB negotiation for current protocols and simply
wire the +5v pins to a common bus protected by a 3 or 4 amp polyfuse.
IOW, your 2 or 3 amp usb charger is unlikely to be kept short of juice
when plugged into a desktop PC.

A laptop, otoh, probably does include the full power control protocol
to minimise excessive demand from its battery (but, even here, this
may not always be the case).


The arrangement in a car adapter is a little different - and there's various
ways of going about it depending how cheap they want to make it.

Possibly the best way is with a switch-mode chip like the industry standard
MC34063 - whether you'll get that for a £ is another matter.

Next time I go into town, I might punt a £ for one just to break open and
see what's in it.

With a limit of just half an amp output, the chinese manufacturer
will be able to get away with mounting the chip straight onto the
circuit board with a blob of protective epoxy to stick it down to the
board (just like those cheap USB flash memory card adapters).

They only have to survive 6 to 12 months before atmospheric pollution
poisons the chip and the punter has to...well, punt another quid their
way. Most Pound shop customers wouldn't bother invoking SOGA over a
one pound item. The Pound shop management rely on this factor but
aren't stupid enough to open this can of worms so will cheerfully
accept any warranty returns with good grace.

If the chip turns out to be under a blob of epoxy on the circuit
board, I'd be a little leary of such a product in this case.
--
Regards, J B Good