Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets
in a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which
seemed ideal. The data leads all went through a chip under a blob of
"sealing wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb
tracks from the chip and a blob of solder on the back of each output
socket has converter the hub to 4 way power distributor that works with
all my devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find
it through google searches hence posting it here hoping it might help
someone else.
Bob

"Bob Minchin" wrote in message
...
Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets in
a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which seemed
ideal. The data leads all went through a chip under a blob of "sealing
wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb tracks
from the chip and a blob of solder on the back of each output socket has
converter the hub to 4 way power distributor that works with all my
devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find it
through google searches hence posting it here hoping it might help someone
else.
Bob

OOI, how do you power it?
Presumably an iphone will pull ~2A, with 3 other feeds where are you getting
5V at say 5A from?

bm wrote:
"Bob Minchin" wrote in message
...
Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets in
a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which seemed
ideal. The data leads all went through a chip under a blob of "sealing
wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb tracks
from the chip and a blob of solder on the back of each output socket has
converter the hub to 4 way power distributor that works with all my
devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find it
through google searches hence posting it here hoping it might help someone
else.
Bob

OOI, how do you power it?
Presumably an iphone will pull ~2A, with 3 other feeds where are you getting
5V at say 5A from?


Iphones and other "smart" devices will only take high current if it is
negotiated up from the base USB limit (not sure what that is). As data
is inhibited, then the negotiation fails and current drawn remains at
the minimum.

The unit is powered by a standard Cigar lighter to usb adaptor

"Bob Minchin" wrote in message
...
bm wrote:
"Bob Minchin" wrote in message
...
Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets
in
a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which
seemed
ideal. The data leads all went through a chip under a blob of "sealing
wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb
tracks
from the chip and a blob of solder on the back of each output socket has
converter the hub to 4 way power distributor that works with all my
devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find
it
through google searches hence posting it here hoping it might help
someone
else.
Bob

OOI, how do you power it?
Presumably an iphone will pull ~2A, with 3 other feeds where are you
getting
5V at say 5A from?


Iphones and other "smart" devices will only take high current if it is
negotiated up from the base USB limit (not sure what that is). As data is
inhibited, then the negotiation fails and current drawn remains at the
minimum.

The unit is powered by a standard Cigar lighter to usb adaptor

Ok Bob, so you can't therefore get a fast charge?
Not trying to pick holes, I thought maybe you'd found a source of 5+A 12 to
5 cigar lighter adapters

In article ,
Bob Minchin writes:
bm wrote:
"Bob Minchin" wrote in message
...
Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets in
a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which seemed
ideal. The data leads all went through a chip under a blob of "sealing
wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb tracks
from the chip and a blob of solder on the back of each output socket has
converter the hub to 4 way power distributor that works with all my
devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find it
through google searches hence posting it here hoping it might help someone
else.
Bob

OOI, how do you power it?
Presumably an iphone will pull ~2A, with 3 other feeds where are you getting
5V at say 5A from?


Iphones and other "smart" devices will only take high current if it is
negotiated up from the base USB limit (not sure what that is). As data
is inhibited, then the negotiation fails and current drawn remains at
the minimum.

The USB power source spec doesn't use USB negotiation, but just
an appropriate resistor network between the supply and data lines
(since power supplies don't generally have any smarts to bring
up a USB data link). This will allow current draw up to 2.4A
with the right resistor network (with various lesser limits down
to 500mA IIRC with different resistor values). Apple uses a different
resistor value signalling from everyone else. There is a simple chip
which will identify Apple/non-Apple device and present the right data
line resistor loads for both, and it also has the ability to measure
and enforce the current limit.

The unit is powered by a standard Cigar lighter to usb adaptor

These are available with up to 2 x 2.4A outputs. CPC often have them
on special offer. (I often buy them to pull apart for 12V/24V to 5V
converters for running Raspberry Pis.)

Note that USB C power sources are more complicated, because the
device can negotiate to raise the voltage well above 5V in order
to get more power down the cable.

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

bm wrote:
"Bob Minchin" wrote in message
...
bm wrote:
"Bob Minchin" wrote in message
...
Having an older car (12yrs), I have no USB sockets to charge/power the
multiplicity of tech that I and the family carry on trips
It seemed to me that the cheapest way to get a strip of 4 or so sockets
in
a convenient package was to look at USB hubs.
I got one from ebay for £1.88 and looking inside the input power leads
were directly connected to the 0v and 5v pins of all sockets which
seemed
ideal. The data leads all went through a chip under a blob of "sealing
wax" but i did not care about that.
However there was a problem, an Iphone would not take charge from simply
the 0v and 5v pins.
Digging onto other chargers I discovered that the two data lines were
joined together (but to nothing else). A quick cut through the pcb
tracks
from the chip and a blob of solder on the back of each output socket has
converter the hub to 4 way power distributor that works with all my
devices.
Fits quite nicely in the car too.

http://i115.photobucket.com/albums/n...psaecy1op4.jpg

Disclaimer: This might be common knowledge but not to me nor did I find
it
through google searches hence posting it here hoping it might help
someone
else.
Bob

OOI, how do you power it?
Presumably an iphone will pull ~2A, with 3 other feeds where are you
getting
5V at say 5A from?


Iphones and other "smart" devices will only take high current if it is
negotiated up from the base USB limit (not sure what that is). As data is
inhibited, then the negotiation fails and current drawn remains at the
minimum.

The unit is powered by a standard Cigar lighter to usb adaptor

Ok Bob, so you can't therefore get a fast charge?
Not trying to pick holes, I thought maybe you'd found a source of 5+A 12 to
5 cigar lighter adapters


I have not need for fast charging but just want to power several devices
at the same time.
I think that high power converters do exist but beware of inferior ones
with poor RFI performance as the "hash" generated can easily block GPS,
Bluetooth and DAB signals etc.
Could be worth making a simple linear regulator with a decent heatsink
and mounting it in the boot or engine bay out of the way or buy a
switchmode one and stick it in a metal box with extra filtering.

En el artículo , Andrew Gabriel
escribió:

These are available with up to 2 x 2.4A outputs. CPC often have them
on special offer. (I often buy them to pull apart for 12V/24V to 5V
converters for running Raspberry Pis.)

That's a clever idea. Thanks for the tip.

--
(\_/)
(='.'=) systemd: the Linux version of Windows 10
(")_(")

On Sunday, 16 October 2016 11:07:43 UTC+1, Bob Minchin wrote:

I think that high power converters do exist but beware of inferior ones
with poor RFI performance as the "hash" generated can easily block GPS,
Bluetooth and DAB signals etc.

I once tested a cheap 0.5A car USB charger. Its conducted emissions were
about 20dB above the limit. On opening it up I found holes in the PBC
for RF filtering components but none were fitted.

John

wrote:
On Sunday, 16 October 2016 11:07:43 UTC+1, Bob Minchin wrote:

I think that high power converters do exist but beware of inferior ones
with poor RFI performance as the "hash" generated can easily block GPS,
Bluetooth and DAB signals etc.

I once tested a cheap 0.5A car USB charger. Its conducted emissions were
about 20dB above the limit. On opening it up I found holes in the PBC
for RF filtering components but none were fitted.

John

I had a "no-name" replacement laptop power unit and one of the cable
cores had failed as it entered the laptop plug. In order to repair it
and fit heatshrink sleeving as a strain relief over my repair I needed
to move the moulded on ferrite suppressor. Having carefully shaved off
the outer plastic it was clear that the inner part was just another
plastic cylinder and would have zero effect on and conducted RFI.

Bob

In article ,
Mike Tomlinson writes:
En el artículo , Andrew Gabriel
escribió:

These are available with up to 2 x 2.4A outputs. CPC often have them
on special offer. (I often buy them to pull apart for 12V/24V to 5V
converters for running Raspberry Pis.)

That's a clever idea. Thanks for the tip.

I did get some feedback from one person who tried this that some of
the ones you find around generate quite a lot of RF noise. He used
one in his glider, and found the RF noise killed the GPS and some
other instruments. I haven't had this issue, but probably haven't
used them in such a critical situation.

I have found the efficiency of them varies. You can measure this
by measuring the voltage and current drawn when feeding a known
load (such as a power resistor). A few of them get worryingly hot
at full load, whereas others don't (and it's not necessarily the
components you might think would get hot - often it's the small
inductor where they've scrimped on the conductor size and/or not
understood the skin effect).

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