Hi. I've bought 5V/2A charger. But I have a problem - with this charger, lan doesn't work, and after few minuts raspberry freeze. What spec. should have usb hub?
With this charger I can charge all older phones but Samsung Galaxy S Duos.
Thx. for any advice.
Re: USB hub as charger not working
On the face of it, that USB hub should be OK. Can you try another supply? If you have a meter. check the voltage as detailed at http://elinux.org/R-Pi_Troubleshooting# ... r_problems.
Re: USB hub as charger not working
Another supply works correctly. Only with this charger I have a problem.
Thx. for troubleshooting link, I'll check it.
Thx. for troubleshooting link, I'll check it.
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bltsandwich1
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Re: USB hub as charger not working
The 2A amperage you are reporting is the troubling part to me. I have always done well with 750mA to1A and haven't ventured beyond. Is the rating you have for the secondary charger (the one that works) the same as the primary, or does it report a lower amperage?
Hope this helps!
John
Hope this helps!
John
facebook.com/chicagoraspberryjam - join in the fun
Majoring in ChemE at the University of Houston.
Majoring in ChemE at the University of Houston.
Re: USB hub as charger not working
You don't understand 'amperage'. The current drawn is determined by the RPi not the power supply. It is no problem to have a supply that can deliver 2 amps.bltsandwich1 wrote:The 2A amperage you are reporting is the troubling part to me. I have always done well with 750mA to1A and haven't ventured beyond. Is the rating you have for the secondary charger (the one that works) the same as the primary, or does it report a lower amperage?
Hope this helps!
John
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FTrevorGowen
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- Contact: Website
Re: USB hub as charger not working
Having followed your link to the charger specs. I see it has four USB outputs. If those outputs are mutually isolated then they may be limited to 500mA each** (ie. 2A total = 4 x 0.5). Also for many "chargers", as opposed to "power supplies" the maximum current may actually be the "short-circuit current limit" at which the charger voltage could be close to "zero" volts! For examples of this take a look at my measurements of a few "5V 1A" PSU's and chargers at http://www.cpmspectrepi.webspace.virgin ... plies.html . The wiki also contains notes on working/non-working PSU's at http://elinux.org/RPi_VerifiedPeriphera ... r_adapters .foster24 wrote: Hi. I've bought 5V/2A charger. But I have a problem - with this charger, lan doesn't work, and after few minuts raspberry freeze. What spec. should have usb hub?
With this charger I can charge all older phones but Samsung Galaxy S Duos.
Thx. for any advice.
Trev.
**as per USB specs.
Still running Raspbian Jessie or Stretch on some older Pi's (an A, B1, 2xB2, B+, P2B, 3xP0, P0W, 2xP3A+, P3B+, P3B, B+, and a A+) but Buster on the P4B's. See: https://www.cpmspectrepi.uk/raspberry_pi/raspiidx.htm
Re: USB hub as charger not working
No, if you look at the second photo you can see from the labelling on the unit that it claims to be able to deliver 2 amps if only 1 output is used. (Or 2 outputs at 1 amp each etc.)FTrevorGowen wrote:Having followed your link to the charger specs. I see it has four USB outputs. If those outputs are mutually isolated then they may be limited to 500mA each** (ie. 2A total = 4 x 0.5).foster24 wrote: Hi. I've bought 5V/2A charger. But I have a problem - with this charger, lan doesn't work, and after few minuts raspberry freeze. What spec. should have usb hub?
With this charger I can charge all older phones but Samsung Galaxy S Duos.
Thx. for any advice.
Re: USB hub as charger not working
Thanks for replies.
First - charger gives 5V/2A from one USB slot - I have measured it simultaneously with one voltmeter and one ampermeter. But between TP1 and TP2 on pi I had voltage 3,8 - 4,2V and it was not stable. So this is the problem.
Second - I didn't understand why charger can't get 5V/0,7A. When I bought it I did some measurements and I never measured 5V/2A. The whole problem was with quality of USB cabel. With standard USB cable I measured 1,2A/4V - not more. With USB cable attached to nikon camera, I measured 1,5A/4,5V. But when I soldered on usb connector this rough cable, I measured 5V/2A.
So I think - standard chargers and their fixed cables are rated to their output current. So if my samsung charger give 5V/0,7A, it really gives this current. But when I use USB charger and "some" USB cable, cable manufacturers usually don't count with max. current and cable has high resistance. Also when my charger can give 2A, raspberry take max. current which it can. And with increaing current, increase resistance and decrease voltage. Example:
At 0,7A - 5V - minimal resistance(R) - everythink is ok.
At 0,8A - 4,9V - also min. R
At 0,9A - 4,8V - increased R - but still enough for raspberry
At 1,0A - 4,7V - higher R - not enough for raspberry - fail
Because charger is "too strong", it supply too much current to cables.
Also in this section on wiki it written this type of problems: http://elinux.org/RPi_Hardware#Power_Supply_Problems
So final question is what type of cable should I use, or how to create my own?
First - charger gives 5V/2A from one USB slot - I have measured it simultaneously with one voltmeter and one ampermeter. But between TP1 and TP2 on pi I had voltage 3,8 - 4,2V and it was not stable. So this is the problem.
Second - I didn't understand why charger can't get 5V/0,7A. When I bought it I did some measurements and I never measured 5V/2A. The whole problem was with quality of USB cabel. With standard USB cable I measured 1,2A/4V - not more. With USB cable attached to nikon camera, I measured 1,5A/4,5V. But when I soldered on usb connector this rough cable, I measured 5V/2A.
So I think - standard chargers and their fixed cables are rated to their output current. So if my samsung charger give 5V/0,7A, it really gives this current. But when I use USB charger and "some" USB cable, cable manufacturers usually don't count with max. current and cable has high resistance. Also when my charger can give 2A, raspberry take max. current which it can. And with increaing current, increase resistance and decrease voltage. Example:
At 0,7A - 5V - minimal resistance(R) - everythink is ok.
At 0,8A - 4,9V - also min. R
At 0,9A - 4,8V - increased R - but still enough for raspberry
At 1,0A - 4,7V - higher R - not enough for raspberry - fail
Because charger is "too strong", it supply too much current to cables.
Also in this section on wiki it written this type of problems: http://elinux.org/RPi_Hardware#Power_Supply_Problems
So final question is what type of cable should I use, or how to create my own?
Re: USB hub as charger not working
No, the charger being "too strong" is not the problem. It only supplies whatever current the RPi needs. The charger doesn't "force" more current than the RPi wants.foster24 wrote: Because charger is "too strong", it supply too much current to cables.
Also in this section on wiki it written this type of problems: http://elinux.org/RPi_Hardware#Power_Supply_Problems
So final question is what type of cable should I use, or how to create my own?
USB to micro-USB cables with too much resistance are a common cause of RPi troubles. Ones that are short and have a thick cable are the most likely to be OK.