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Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 3:20 pm
by 386sx
FTrevorGowen wrote:
Tue Jan 08, 2019 2:46 pm
davidcoton wrote:
Thu Jan 03, 2019 11:15 pm
The Stontronics supply was changed from 2A to2A5 about the time the Pi3B was launched, IIRC. 2A was enough for previous models but 2A5 is recommended for the Pi3B and Pi3B+ to allow the full 1A2 for USB devices.
FWIW, having finally acquired the newer version, and had the time to update my webpages, here are my (updated) measurements of the (static) current loading of both versions of the (Stontronics) PSU:
http://www.cpmspectrepi.uk/raspberry_pi ... _Models.29
Trev.
Interesting, thank.

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 3:42 pm
by marcosbong
386sx wrote:
Tue Jan 08, 2019 3:20 pm
FTrevorGowen wrote:
Tue Jan 08, 2019 2:46 pm
davidcoton wrote:
Thu Jan 03, 2019 11:15 pm
The Stontronics supply was changed from 2A to2A5 about the time the Pi3B was launched, IIRC. 2A was enough for previous models but 2A5 is recommended for the Pi3B and Pi3B+ to allow the full 1A2 for USB devices.
FWIW, having finally acquired the newer version, and had the time to update my webpages, here are my (updated) measurements of the (static) current loading of both versions of the (Stontronics) PSU:
http://www.cpmspectrepi.uk/raspberry_pi ... _Models.29
Trev.
Interesting, thank.
Usefull graphics, thanks :P

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 3:57 pm
by jahboater
jamesh wrote:
Tue Jan 08, 2019 1:11 pm
Worth noting the Official PS is actually 5.1v at the wall end, and uses thick copper wires, so by the time the power gets to the Pi itself, its dropped only slightly to 5v.
I think its better than that. The cable is "fixed" so the specified voltage is measured at the end of the cable, at the Pi end.
The heavy 18AWG cable helps ensure that the voltage at the Pi end doesn't vary much with a changing load.

I believe that is why it is only 5.1V and not 5.2V because that would have caused problems with older Pi models that didn't have the fancy voltage regulator.

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 4:12 pm
by W. H. Heydt
jahboater wrote:
Tue Jan 08, 2019 3:57 pm
I believe that is why it is only 5.1V and not 5.2V because that would have caused problems with older Pi models that didn't have the fancy voltage regulator.
Hard to say... 5.2v is still within the USB spec. More likely it's to keep the manufacturing tolerances to within the specification upper bound of 5.25v.

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 4:25 pm
by KoolDud3
uilfut wrote:
Fri Mar 16, 2018 1:04 am
This was mentioned in the launch video, but struggling with current 2A random adapters which have always worked for me with pis in the past.

Official raspberry pi adapter is a lot of dollars shipped to Canada. On the lookout for something local... any ideas? 2.5A seems rarer than 2A.
I have the official power by raspberry pi. It runs on 5V 2A and works fine.

Oh, and i have an rpi 3 B+

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 8:57 pm
by Imperf3kt
To those recommending the official PSU, I'll just leave this quote as a friendly reminder of what power supply we are discussing.
marcosbong wrote:
Thu Jan 03, 2019 11:04 pm
Hello.
Anybody here knows why I have an official Raspberry pi power supply made by Stontronics, but rated 2A ?

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 9:09 pm
by HawaiianPi
KoolDud3 wrote:
Tue Jan 08, 2019 4:25 pm
I have the official power by raspberry pi. It runs on 5V 2A and works fine.

Oh, and i have an rpi 3 B+
As already stated, the OLDER official power supply was rated for 5V at up to 2A. The newer one is 2.5A, and the 2.5A rating includes 1.2A for the USB port power.

Your Pi 3B+ runs fine on 2A because you don't have any power hungry accessories attached (but you only have 700mA available for those, which is 42% less than with the newer PSU).

Re: pi3b+ needs better power supply

Posted: Tue Jan 08, 2019 9:29 pm
by HawaiianPi
jamesh wrote:
Tue Jan 08, 2019 1:11 pm
Worth noting the Official PS is actually 5.1v at the wall end, and uses thick copper wires, so by the time the power gets to the Pi itself, its dropped only slightly to 5v.
I thought that power supplies with built-in power cords were rated at the output plug, not the wall-wart?

My official PSU outputs a little over 5.1V when measured on my running Pi 3B+ computer.

Re: pi3b+ needs better power supply

Posted: Thu May 23, 2019 5:07 pm
by widgetphreak
To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.

Re: pi3b+ needs better power supply

Posted: Fri May 24, 2019 4:14 pm
by ejolson
widgetphreak wrote:
Thu May 23, 2019 5:07 pm
To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.
Sorry about your Rhino problems. Age old wisdom I learned in school is that the way to stop a rhino from charging is to take away its credit card. Unfortunately, it was not discussed in school how to make a Rhino charge, which seems closer to what you need.

I think it is possible to disable the gigabit Ethernet and down clock the Pi 3B+ to reach power-consumption levels and functionality similar to the 3B. That way you can retain the other benefits of the 3B+ which include better heat dissipation and regulation of the internal 3V supply used to power the SOC.

Re: pi3b+ needs better power supply

Posted: Fri May 24, 2019 8:33 pm
by jamesh
ejolson wrote:
Fri May 24, 2019 4:14 pm
widgetphreak wrote:
Thu May 23, 2019 5:07 pm
To complicate matters further, Frys Electronics in the US is selling Power Supplies for the RPi made by a company called Rhino... the box specifically says "Supports Raspberry Pi 2,3, 3B,& 3B+"
Don't believe the box... I bought a 3B+ from Frys and that adapter to go with it... got it home, downloaded fresh image... Powered it up... yellow lightningbolt the entire time. Installed Kodi... menu browsing slow as heck... try to queue a playlist of videos... significantly longer pause between videos. Install emulation station... load up Tony Hawk on PS-ONE... game freezes for a solid second every 19 seconds or so.

I've been running the thing under-clocked for the last month just to get by... and I've finally decided to just offer it up for trade on Facebook Marketplace locally for a 3B [nonplus]. I can power my other 3B from a USB Battery Power Brick no problem... the 3B+ won't even load the OS while being powered by a USB Battery. I hope Element 14 is not planning to completely discontinue the 3B [nonplus] because honestly it is NOT worth all these Power Supply hassles... and losing the ability to Power it from an off-the-shelf USB Battery just to gain Gigabit Ethernet and a couple extra Mhz.
Sorry about your Rhino problems. Age old wisdom I learned in school is that the way to stop a rhino from charging is to take away its credit card. Unfortunately, it was not discussed in school how to make a Rhino charge, which seems closer to what you need.

I think it is possible to disable the gigabit Ethernet and down clock the Pi 3B+ to reach power-consumption levels and functionality similar to the 3B. That way you can retain the other benefits of the 3B+ which include better heat dissipation and regulation of the internal 3V supply used to power the SOC.
Or just get a decent power supply.

Re: pi3b+ needs better power supply

Posted: Fri May 24, 2019 8:41 pm
by Andyroo
jamesh wrote:
Fri May 24, 2019 8:33 pm
...
Or just get a decent power supply.
:lol:
Way too easy - pass me the soldering iron - I'm going in...

Sorry - its been a long day and I feel as bad as my jokes.