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  • Re: USB C power supply for Pi2?

    From David Taylor@3:770/3 to bob prohaska on Tue Oct 18 18:53:38 2022
    On 18/10/2022 18:32, bob prohaska wrote:
    It turns out my Pi2 problems were yet another dying power supply.

    I can easily splice the old power cord onto a new wallwart, but
    wonder if it's possible to use a USB C adapter that might remain
    useful after the Pi2 is obsolete.

    AIUI USB C power supplies can deliver up to 20 volts after negotiating
    with the load. Less clear is how the negotiating is done and what happens
    if a C power supply is connected to a Pi2 which can't negotiate.

    Anybody tried it?

    Thanks for reading,

    bob prohaska

    Bob,

    I've been going for power supplies which say they are 5V, such as the official RPi-4 USB-C ones. No mention there of having the higher-voltage options. Beware of xPhone "compatible" ones.

    --
    Cheers,
    David
    Web: https://www.satsignal.eu

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From bob prohaska@3:770/3 to All on Tue Oct 18 17:32:28 2022
    It turns out my Pi2 problems were yet another dying power supply.

    I can easily splice the old power cord onto a new wallwart, but
    wonder if it's possible to use a USB C adapter that might remain
    useful after the Pi2 is obsolete.

    AIUI USB C power supplies can deliver up to 20 volts after negotiating
    with the load. Less clear is how the negotiating is done and what happens
    if a C power supply is connected to a Pi2 which can't negotiate.

    Anybody tried it?

    Thanks for reading,

    bob prohaska

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From nospam@3:770/3 to dave@davehigton.me.uk on Tue Oct 18 15:29:08 2022
    In article <9eb76f395a.DaveMeUK@BeagleBoard-xM>, David Higton <dave@davehigton.me.uk> wrote:

    A USB charger is not intended to run 24/365.

    yes they are.

    Depending on how much you
    run your Pi2, you may find you're better off with a proper power supply.

    usb chargers are proper, except perhaps noname junk that's best avoided.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Martin Gregorie@3:770/3 to nospam on Tue Oct 18 20:06:06 2022
    On Tue, 18 Oct 2022 15:29:08 -0400, nospam wrote:

    In article <9eb76f395a.DaveMeUK@BeagleBoard-xM>, David Higton <dave@davehigton.me.uk> wrote:

    A USB charger is not intended to run 24/365.

    There are actually three classes of 'PSU's, all designed for different use cases:

    1) *battery charger*, which is designed for intermittent use, typically
    it is only in use for a small fraction of its duty cycle. That's
    because its job is to top off the battery it's attached to and then
    set its 'charge complete' indicator and shut down.
    It is NOT designed for continuous operation.

    2) *PSU*, USB or not. These are designed to run 24/7, but offer no
    protection against mains failure

    3) 'uninterruptable power supply', which is designed to keep its load
    powered regardless of interruptions of its power source, though the
    length of time it can provide power will be specified. Longer costs
    more.

    It pays to think about which of those classes you actually want before installing anything: picking the wrong type for your application is likely
    to be unsatisfactory. And be careful to over-specify rather then under-
    specify your power source as well as considering its use case because that
    will extend its life.


    Depending on how much you run your Pi2, you may find you're better off
    with a proper power supply.

    Spot on. There's a fourth case too: the 'piece of crap'. Avoid at all
    costs.



    --

    Martin | martin at
    Gregorie | gregorie dot org

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Chris Green@3:770/3 to bob prohaska on Tue Oct 18 21:10:50 2022
    bob prohaska <bp@www.zefox.net> wrote:
    It turns out my Pi2 problems were yet another dying power supply.

    I can easily splice the old power cord onto a new wallwart, but
    wonder if it's possible to use a USB C adapter that might remain
    useful after the Pi2 is obsolete.

    AIUI USB C power supplies can deliver up to 20 volts after negotiating
    with the load. Less clear is how the negotiating is done and what happens
    if a C power supply is connected to a Pi2 which can't negotiate.

    The USB-C power interface is a total can of worms IMHO, it is far, far
    too complex and the chances of buying a supply that implements it
    completely or properly are minimal.

    Anything that uses much more than the extra current available at 5
    volts probably needs to be specific to the device manufacturer to be
    safe.

    --
    Chris Green
    ·

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From A. Dumas@3:770/3 to bob prohaska on Wed Oct 19 01:50:16 2022
    bob prohaska <bp@www.zefox.net> wrote:
    It turns out my Pi2 problems were yet another dying power supply.

    Just get the effing official power supply already. Maybe it's $2 more but
    that is definitely worth it.

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Deloptes@3:770/3 to Chris Green on Wed Oct 19 07:45:54 2022
    Chris Green wrote:

    The USB-C power interface is a total can of worms IMHO, it is far, far
    too complex and the chances of buying a supply that implements it
    completely or properly are minimal.


    what about the micro-USB?

    Also what about using only the +5V and negative (red/black) - what kind of negotiations are you talking about?!

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Ahem A Rivet's Shot@3:770/3 to Chris Green on Wed Oct 19 06:56:28 2022
    On Tue, 18 Oct 2022 21:10:51 +0100
    Chris Green <cl@isbd.net> wrote:

    The USB-C power interface is a total can of worms IMHO, it is far, far
    too complex and the chances of buying a supply that implements it
    completely or properly are minimal.

    The chip makers are all over this - there will undoubtedly be a few
    bad ones but they should fall out of use pretty quickly or get fixed. WiFi
    and Bluetooth are *way* more complex but all a manufacturer has to do to
    get it right is use a decent chip.

    --
    Steve O'Hara-Smith
    Odds and Ends at http://www.sohara.org/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Chris Green@3:770/3 to Deloptes on Wed Oct 19 08:30:26 2022
    Deloptes <deloptes@gmail.com> wrote:
    Chris Green wrote:

    The USB-C power interface is a total can of worms IMHO, it is far, far
    too complex and the chances of buying a supply that implements it completely or properly are minimal.


    what about the micro-USB?

    The 'old' micro-USB is fairly straightforward, usually. I think there
    are some possible extras but basically the only real 'extra' is the availability of more current from some PSUs.


    Also what about using only the +5V and negative (red/black) - what kind of negotiations are you talking about?!

    On USB-C the source and client can 'negotiate' all sorts of changes to
    the basic 5 volt supply, it can be negotiated up to 12 volts or even
    20 volts. The 'negotiation' comprises signals on the other pins of
    the connector so (as far as I understand it) if you only connect to
    the 0v and +ve supply pins you should only ever get 5 volts.

    --
    Chris Green
    ·

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Kees Nuyt@3:770/3 to martin@mydomain.invalid on Wed Oct 19 17:48:34 2022
    On Tue, 18 Oct 2022 20:06:07 -0000 (UTC), Martin Gregorie <martin@mydomain.invalid> wrote:

    There are actually three classes of 'PSU's, all designed for different use >cases:

    1) *battery charger*, which is designed for intermittent use, typically
    it is only in use for a small fraction of its duty cycle. That's
    because its job is to top off the battery it's attached to and then
    set its 'charge complete' indicator and shut down.
    It is NOT designed for continuous operation.

    Many of these can negotiate with the device they are charging to
    supply a higher voltage / current.

    2) *PSU*, USB or not. These are designed to run 24/7, but offer no
    protection against mains failure

    They are supposed to deliver a fixed voltage. No negotiation.
    The device determines how much current it will pull at any
    moment, up to a PSU specific maximum current.
    --
    Kees Nuyt

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Andy Burns@3:770/3 to Chris Green on Fri Oct 21 08:43:18 2022
    Chris Green wrote:

    On USB-C the source and client can 'negotiate' all sorts of changes to
    the basic 5 volt supply, it can be negotiated up to 12 volts or even
    20 volts.

    Latest USB PD spec allows 48V @ 5A

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)
  • From Ahem A Rivet's Shot@3:770/3 to Andy Burns on Fri Oct 21 10:43:46 2022
    On Fri, 21 Oct 2022 08:43:19 +0100
    Andy Burns <usenet@andyburns.uk> wrote:

    Latest USB PD spec allows 48V @ 5A

    Nice cheap, warm cables.

    --
    Steve O'Hara-Smith
    Odds and Ends at http://www.sohara.org/

    --- SoupGate-Win32 v1.05
    * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3)