Master Plug Dual USB Power supply 70% off Sainsburys

spudy12 said:

Hi there!

First post here, mainly just to say thanks! Saw this thread and went and bought one just now! Really good find there, well done!

As i see some people are on about SD cards, I also just ordered this off of amazon

SanDisk 8GB 30MB/s Extreme HD Video SDHC Card - only £10.62 if anyone is interested! 

Here is a link

http://www.amazon.co.uk/gp/pro.....B00422FBJ2

Spudd

That's a Class 10 card. Watch out, the FAQ says that Class 10 cards can be problematic: http://elinux.org/RPi_Verified.....SDHC_cards

Maplin "High Power USB Charger with Travel Adapters" (N06JT) is on sale for half price, £9.99. No idea of quality or full specs but their leaflet says "2.1A output" and the main plug body has two USB output sockets.

"Supplied with UK, USA, European and Australisian power plugs" so perhaps ideal for the jet-setter travelling the world with their R-Pi.

Found url of lidl charger:
http://www.lidl.co.uk/cps/rde/.....=noservice

Dual usb hub & card reader (up to 4gb) too!

Paulie

paulie said:

Found url of lidl charger:
http://www.lidl.co.uk/cps/rde/.....=noservice

Dual usb hub & card reader (up to 4gb) too!

Paulie

No PSU with that.  "Charges your mobile from PC " ie USB powered and passive hub.

Doh!
Seemed good value up to that point.
My RTFM error, sorry.

Good news!

A week ago.. I just found a final black master plug at Sainsburys for 7.49, but they were pushing the white ones at 15 quid still.. for the same thing in a different colour - even the staff were bemused, but saying the reason was 'computer says' that the white ones were a continually stocked item, whereas the black were for the promo.

(I wanted black to use with RPi, white for iPhone)

This has obviously changed. Now today, I got a white one for 7.49 and the black ones are reduced to 5.49.

Also, I noticed that B&Q have a similar looking item with 4 surge protected mains sockets on for around 8 quid - unfortunately can't find a link for that online.

I can confirm that my local Sainsbury's is doing the 2 USB, plug-through surge protector at £7.49, seems to be the normal price. Have grabbed one and will probably grab another next time I am there, useful just as a mobile charger that doesn't use up a socket.

In the end, I was lucky to pick up one of these while they were still £4.49...

Ironically, I might not end up using it for the RasPi, if a powered USB hub can handle powering the machine as well as doing USB data duties. Does anyone have any thoughts on whether this is a good idea or not?

(The adapter is going in my "gadget bag" regardless - it is great to have on a train, when there is only one power point (if any)!)

I have a USB charger that runs 5v 2amps. This is enough, correct?

Kerblamm said:

I have a USB charger that runs 5v 2amps. This is enough, correct?

Yes, more than enough for an RP (either model) and two USB peripherals that each require up to slightly more than 100 mA.  Thirstier peripherals cannot be powered from the RP's USB sockets.

Thank you!

I bought a single USB socket Masterplug model USBPLGW from Sainsburys last week, £2.99, reduced from £3.99.  Great for charging most devices, but not for powering a Raspberry Pi.  Label states: 5V at 1A.  I tested it under load:

No load (open circuit): voltage 4.88V

10 ohm load: voltage 4.57V (gives current = 457mA)

5 ohm load: voltage 4.17V (gives current = 834mA)

Raspberry Pi data seems to say 4.75V to 5.25V supply is required, must be capable of providing at least 700mA at 5V.

Admittedly I only bought and tested the one, but I doubt that others of the same type are adequate under raspberry Pi load.

framil said:

I bought a single USB socket Masterplug model USBPLGW from Sainsburys last week, £2.99, reduced from £3.99.  Great for charging most devices, but not for powering a Raspberry Pi.  Label states: 5V at 1A.  I tested it under load:

No load (open circuit): voltage 4.88V

10 ohm load: voltage 4.57V (gives current = 457mA)

5 ohm load: voltage 4.17V (gives current = 834mA)

Raspberry Pi data seems to say 4.75V to 5.25V supply is required, must be capable of providing at least 700mA at 5V.

Admittedly I only bought and tested the one, but I doubt that others of the same type are adequate under raspberry Pi load.

I bought a USBPLGB (same, but black version) from Sainsbury's.  In the absense of my Pi (two weeks to go...) I just measured the output.

No load (open circuit) 4.92v

10ohm load 4.98v

5ohm load 4.78v

Data lines at 2.0v and 2.5v (according to wikipedia, apple chargers have one line at 2.0v, the other at 2.8v, to indicate a 1A capable charger).

That was measured via a normal metre-ish length USB A-B cable (not a micro one) plugged into a PCB mount socket (not fitted to a PCB, no device).
And noise wise just a few mV of ac according to the Fluke (didn't look on a scope).

So looks good to me.  Pi-tastic!

dom.

As you'll see earlier in this thread, I bought one of these Master Plug Dual USB units a couple of months ago, when Sainsbury's were selling them off at £4.49. Now I have my RasPi (it came yesterday), I have an initial "report"...

In short: the charger powers the RasPi, but there are signs that the power isn't always sufficient somewhere along the line. I am currently using a 2.4GHz wireless keyboard/trackball from Maplin (looks as if it's no longer in their catalogue), and although it mostly works, I get the "stuck characters" and intermittent missed keypresses problem, which the Pi FAQ suggests indicates insufficient power over USB.

I'm using a Belkin 7-port powered USB hub (the silver equivalent of the F5U237QEA) for peripherals only, and the USB dongle for the keyboard is currently plugged directly into the Pi, so I'll try moving it to the hub and see if that solves the problem (or creates its own).

It's early days yet, but I'm not 100% convinced the Master Plug is delivering enough power (or it could be the Nokia micro-USB cable I'm using). We'll see how things go over the weekend...

I also have one of these Sainsbury's dual usb power supply plugs, bought in preparation for the RPi (which I haven't yet received). I also bought a USB 'Y' cable from Amazon, i.e. dual USB A plugs to a micro B plug that will fit my RPi. If the output of the Sainsbury's USB sockets is only 0.5 amps per socket, presumably I could plug in both USB plugs from my cable to deliver a total of 1 amp to the micro B plug. Am I correct in thinking this? I would be grateful for any advice.

I bit the bullet a couple of weeks back and got one of these http://www.maplin.co.uk/compact-twin-usb-power-supply-562310

More than I wanted to pay for a psu, but the shops just round the corner from where I work and it did stop my RasPi hanging.

I'm going to look for a Nokia AC-10X - I hear they deliver about 1.2A, and Amazon's got them for £3-4...

BTW - as I posted earlier, perhaps someone could add a section to the wiki, to list USB chargers which don't cause the Pi problems?

The IPAD power socket is great for the pi as its 2.3amps. Powered my wireless keyboard/mouse dongle.

1.5amp 5 volt power supply with micro usb

http://www.shopness.co.uk/en/raspberry-pi-accesories/84-raspberry-pi-5v-power-supply-usb-mains-adaptor-.html

framil said:


I bought a single USB socket Masterplug model USBPLGW from Sainsburys last week, £2.99, reduced from £3.99.  Great for charging most devices, but not for powering a Raspberry Pi.  Label states: 5V at 1A.  I tested it under load:

No load (open circuit): voltage 4.88V

10 ohm load: voltage 4.57V (gives current = 457mA)

5 ohm load: voltage 4.17V (gives current = 834mA)

Raspberry Pi data seems to say 4.75V to 5.25V supply is required, must be capable of providing at least 700mA at 5V.

Admittedly I only bought and tested the one, but I doubt that others of the same type are adequate under raspberry Pi load.


I bought a USBPLGB (same, but black version) from Sainsbury's.  In the absense of my Pi (two weeks to go...) I just measured the output.

No load (open circuit) 4.92v

10ohm load 4.98v

5ohm load 4.78v

Data lines at 2.0v and 2.5v (according to wikipedia, apple chargers have one line at 2.0v, the other at 2.8v, to indicate a 1A capable charger).

That was measured via a normal metre-ish length USB A-B cable (not a micro one) plugged into a PCB mount socket (not fitted to a PCB, no device).
And noise wise just a few mV of ac according to the Fluke (didn't look on a scope).

So looks good to me.  Pi-tastic!

dom.

I have revisited this and found that the USB cable I used for my test (cut from a defunct optical mouse!) has quite a high resistance. I repeated the test with another USB cable and got very good results:
No load (open circuit): 4.88V

10 ohm load: 5.04V

5 ohm load: 5.01V

Apologies for my misleading earlier post. Pi-tastic - indeed!

I use a power supply from my Linux based Nokia N900 (ARM Cortex A8) and works great

You can get it on newegg.com
http://www.newegg.com/Product/Product.a ... 07R03A6981


Here are the specs: Learn more about the Nokia AC-10U
General

Brand
Nokia

Model
AC-10U

Type
Charger & Adapter

Color
Black

Compatibility

Compatible Phone Manufacturer
For devices with a micro USB charging interface

Spec

Specifications
Physical features and interface:

- Dimensions: 1.10 x 2.95 x 2.75 in (E), 1.97 x 2.95 x 2.36 in (X)

- Weight: 2.5-2.89 oz (depending on country variants)

- Cable length: 70.87 in

- Connectors micro USB charging connector

- Cable management: Velcro strip

- Operating temperature: 23°F to 113°F

Power:

- Input voltage: 100-240V AC 50/60Hz

- Output current: 1200 mA

- Standby power consumption: < 30 mW

- Nokia High Efficiency Charger AC-10U is Energy Star v.2.0 compliant, meeting strict energy-efficiency criteria

Manufacturer Warranty

Parts
2 years limited

Labor
2 years limited