Topics

USB Power

Dane Trethowan <grtdane@...>
 

Hi,
I’ve changed the subject line a little so both to avoid confusion and to explain other devices which are available.
The same retailer in Australia sells a wide variety of USB Power supplies including a multi voltage “Plug Pack” variety which comes with a USB plug as well as the standard lot of plugs to power most other devices.
A blind person has to set the voltage of this “Plug Pack” to the USB setting which its indicated on. The bottom of the unit with the voltage adjustment screw and it can be adjusted by someone without vision counting up from 3 volts.
I also appreciate that this method does take a little time so therefor I think one would be better off by using a straight USB power supply which are readily available.
Apple sell a 12 watt version of this for $20 which I think is very good value.
As for charging cables/ Well again Apple have plenty of these to suit most needs.

On 12 Aug 2019, at 2:55 am, Aman Singer <aman.singer@...> wrote:

Hi,

I'm not sure what you mean by such cables, but if you mean usb A to
barbell connectors, they do exist
https://www.startech.com/ca/Cables/USB-2.0/USB-Adapters/usb-5v-dc-type-m-pow
er-cable-3ft~USB2TYPEM
just for example. If you're asking about USB to 12 bolts, these also exist.
Keep in mind, though, usb A/B is limited to 15 Wats at best. Therefore, when
you go up to 12 volts, you will end up, assuming perfect conversion which
you will never get, at 1.25 A. This will never happen, as I said, the
transformers I've seen:
http://amzn.com/B074R7FDCR
say they'll give 0.8 A at 12 volts (9 wats). In my view, they're
being seriously optimistic, but I haven't used one and hope I'm wrong about
that last point. Even assuming the specs are right about the real world, it
will be a very few devices which will run on 12 volt and less than 1 amp. I
have hopes of USB C for this, it would be really nice to use a single plug
for anything up to 60 wats and up to 20 volts.
HTH,
Aman




-----Original Message-----
From: all-audio@groups.io [mailto:all-audio@groups.io] On Behalf Of Brian
Olesen
Sent: Sunday, August 11, 2019 8:38 AM
To: all-audio@groups.io
Subject: Re: [all-audio] Variable Voltage/Current Power Supply

So you say that such cables exists?

Brian

-----Oprindelig meddelelse-----
Fra: all-audio@groups.io <all-audio@groups.io> På vegne af Dane Trethowan
Sendt: 11. august 2019 11:23
Til: all-audio@groups.io
Emne: Re: [all-audio] Variable Voltage/Current Power Supply

No problem whatever.


-----Original Message-----
From: all-audio@groups.io <all-audio@groups.io> On Behalf Of Brian Olesen
Sent: Sunday, 11 August 2019 6:30 PM
To: all-audio@groups.io
Subject: Re: [all-audio] Variable Voltage/Current Power Supply

Hi Dane,
Really really cool although I don't use such anymore stuff much these days.
But can you find prebuild cables with plugs let's say for usb, so you can
charge a device with 5 volts and connect other stuff with for example 12
volts DC? That would be really neet.
5 amps is a nice portion of power though. smile Brian

-----Oprindelig meddelelse-----
Fra: all-audio@groups.io <all-audio@groups.io> På vegne af Dane Trethowan
Sendt: 10. august 2019 23:43
Til: all-audio@groups.io
Emne: [all-audio] Variable Voltage/Current Power Supply

Hi everyone,

I know there are a few people out there who are into Electronic and DIY
projects of the same nature like me.

Up until now I've found it very difficult to find power supply units that
can be set accurately without vision and offering stable Yes, some
"Plugpack" units will allow quite a bit of flexibility these days but let's
face it, these units are of a low quality usually and don't last too long.

Not only that they don't have the voltage or current range required for good
testing and are subject to RF interference or contribute to the RF
interference in the immediate environment, as if we don't have enough of
that already.

I've found a Power Supply unit which is easy to set for blind people,
incredibly accurate and incredibly quiet as far as RF noise goes.

You can see the power supply at
https://www.jaycar.com.au/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP3840
?utm_campaign=redirect
<https://www.jaycar.com.au/0-to-30vdc-0-to-5a-regulated-power-supply/p/MP384
0?utm_campaign=redirect&utm_source=MP3840r&utm_medium=web>
&utm_source=MP3840r&utm_medium=web

I'm writing from Australia so residents of the US will have to do a bit of
digging to find a similar unit though residents of the UK shouldn't have any
trouble sourcing this supply as Jaycar also do business in the UK.

As you can see the supply has a voltage range of 0 to 30 volts and 0 to 5
amps so any value can be set in these ranges even fine voltage adjustments
can be made - say 1.2 volts -.

The supply has 2 jog-dials on the face to control volts and amps.

These dials click when turned and push in.

Suppose you wanted to adjust the voltage to 4.5 volts.

After turning the supply on you would press the voltage jog-dial once and
turn 4 clicks clockwise, press the jog-dial in to advance to the next unit
and turn the dial clickwise 5 clicks.

The beauty of this supply is that you hear a beep when you've reached the
minimum or maximum value so you can count up or down by click from these
points, the count doesn't wrap around so once you're say at 30 volts the
unit will beep and stay at 30 volts unless you turn the voltage dial anti
clockwise to bring the voltage count down.

The supply remembers the last settings made when the power is turned off.

I have also discovered power supplies available where voltage and current
values can be set via an IOS or Android App.





















Aman Singer
 

Hi Dane and all,

I don't think Brian, and he can correct me of course, was asking about getting from mains power or 12 volt power to USB. I may be wrong, but I don't think that was what he was after because from 120-240 volts to USB is very easy and common, such transformers are very cheap and easy to get. Apple's are quite good, as you say, but there are tons of manufacturers and though some are better than others, they're usually more or less usable. The same may be said of 12-24 volts to USB, again, these are very easy to get. What isn't so easy to get is USB out to another voltage. That is, cables making that USB 5 volt output into something else, whether a non-USB connector or an increased voltage. This is useful in allowing portable USB batteries, which are very common, to power non-USB devices. As I said, I hope USB C makes this easier. I agree with you, there is usually no issue for blind people with standard power adapters providing USB output and if I wanted USB power, I would probably use a dedicated supply anyhow. I would do that because many USB devices are not tolerant of problematic power and I would want something that gives them reasonably clean power so I don't have to worry about where the problems are coming from. As I said, I haven't seen a really usable transformer from USB to 9/12 volts, but that has nothing to do with accessibility.
Aman

-----Original Message-----
From: all-audio@groups.io [mailto:all-audio@groups.io] On Behalf Of Dane Trethowan
Sent: Sunday, August 11, 2019 1:13 PM
To: all-audio@groups.io
Subject: [all-audio] USB Power

Hi,
I’ve changed the subject line a little so both to avoid confusion and to explain other devices which are available.
The same retailer in Australia sells a wide variety of USB Power supplies including a multi voltage “Plug Pack” variety which comes with a USB plug as well as the standard lot of plugs to power most other devices.
A blind person has to set the voltage of this “Plug Pack” to the USB setting which its indicated on. The bottom of the unit with the voltage adjustment screw and it can be adjusted by someone without vision counting up from 3 volts.
I also appreciate that this method does take a little time so therefor I think one would be better off by using a straight USB power supply which are readily available.
Apple sell a 12 watt version of this for $20 which I think is very good value.
As for charging cables/ Well again Apple have plenty of these to suit most needs.


On 12 Aug 2019, at 2:55 am, Aman Singer <aman.singer@...> wrote:

Hi,

I'm not sure what you mean by such cables, but if you mean usb A to
barbell connectors, they do exist
https://www.startech.com/ca/Cables/USB-2.0/USB-Adapters/usb-5v-dc-type
-m-pow
er-cable-3ft~USB2TYPEM
just for example. If you're asking about USB to 12 bolts, these also exist.
Keep in mind, though, usb A/B is limited to 15 Wats at best.
Therefore, when you go up to 12 volts, you will end up, assuming
perfect conversion which you will never get, at 1.25 A. This will
never happen, as I said, the transformers I've seen:
http://amzn.com/B074R7FDCR
say they'll give 0.8 A at 12 volts (9 wats). In my view, they're
being seriously optimistic, but I haven't used one and hope I'm wrong
about that last point. Even assuming the specs are right about the
real world, it will be a very few devices which will run on 12 volt
and less than 1 amp. I have hopes of USB C for this, it would be
really nice to use a single plug for anything up to 60 wats and up to 20 volts.
HTH,
Aman




-----Original Message-----
From: all-audio@groups.io [mailto:all-audio@groups.io] On Behalf Of
Brian Olesen
Sent: Sunday, August 11, 2019 8:38 AM
To: all-audio@groups.io
Subject: Re: [all-audio] Variable Voltage/Current Power Supply

So you say that such cables exists?

Brian

-----Oprindelig meddelelse-----
Fra: all-audio@groups.io <all-audio@groups.io> På vegne af Dane
Trethowan
Sendt: 11. august 2019 11:23
Til: all-audio@groups.io
Emne: Re: [all-audio] Variable Voltage/Current Power Supply

No problem whatever.


-----Original Message-----
From: all-audio@groups.io <all-audio@groups.io> On Behalf Of Brian
Olesen
Sent: Sunday, 11 August 2019 6:30 PM
To: all-audio@groups.io
Subject: Re: [all-audio] Variable Voltage/Current Power Supply

Hi Dane,
Really really cool although I don't use such anymore stuff much these days.
But can you find prebuild cables with plugs let's say for usb, so you
can charge a device with 5 volts and connect other stuff with for
example 12 volts DC? That would be really neet.
5 amps is a nice portion of power though. smile Brian

-----Oprindelig meddelelse-----
Fra: all-audio@groups.io <all-audio@groups.io> På vegne af Dane
Trethowan
Sendt: 10. august 2019 23:43
Til: all-audio@groups.io
Emne: [all-audio] Variable Voltage/Current Power Supply

Hi everyone,

I know there are a few people out there who are into Electronic and
DIY projects of the same nature like me.

Up until now I've found it very difficult to find power supply units
that can be set accurately without vision and offering stable Yes,
some "Plugpack" units will allow quite a bit of flexibility these days
but let's face it, these units are of a low quality usually and don't last too long.

Not only that they don't have the voltage or current range required
for good testing and are subject to RF interference or contribute to
the RF interference in the immediate environment, as if we don't have
enough of that already.

I've found a Power Supply unit which is easy to set for blind people,
incredibly accurate and incredibly quiet as far as RF noise goes.

You can see the power supply at
https://www.jaycar.com.au/0-to-30vdc-0-to-5a-regulated-power-supply/p/
MP3840
?utm_campaign=redirect
<https://www.jaycar.com.au/0-to-30vdc-0-to-5a-regulated-power-supply/p
/MP384 0?utm_campaign=redirect&utm_source=MP3840r&utm_medium=web>
&utm_source=MP3840r&utm_medium=web

I'm writing from Australia so residents of the US will have to do a
bit of digging to find a similar unit though residents of the UK
shouldn't have any trouble sourcing this supply as Jaycar also do business in the UK.

As you can see the supply has a voltage range of 0 to 30 volts and 0
to 5 amps so any value can be set in these ranges even fine voltage
adjustments can be made - say 1.2 volts -.

The supply has 2 jog-dials on the face to control volts and amps.

These dials click when turned and push in.

Suppose you wanted to adjust the voltage to 4.5 volts.

After turning the supply on you would press the voltage jog-dial once
and turn 4 clicks clockwise, press the jog-dial in to advance to the
next unit and turn the dial clickwise 5 clicks.

The beauty of this supply is that you hear a beep when you've reached
the minimum or maximum value so you can count up or down by click from
these points, the count doesn't wrap around so once you're say at 30
volts the unit will beep and stay at 30 volts unless you turn the
voltage dial anti clockwise to bring the voltage count down.

The supply remembers the last settings made when the power is turned off.

I have also discovered power supplies available where voltage and
current values can be set via an IOS or Android App.