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  • darvinya

    titán

    válasz Batman2 #33054 üzenetére

    Gyári töltő 100Hz-es 5V-ot ad.

    Made Robot by Robot −Xiaomi 12T Pro gyászruhás / '06 Focus kombi szürke

  • Kernel

    nagyúr

    válasz Batman2 #33054 üzenetére

    Én is barkácsoltam már USB-kábellel, de nem mertem volna tisztán Internetes rajzokra támaszkodni, vagyis azt saját mérésekkel támogattam meg, gondolok itt feszültség és ellenállásmérésre is, feladattól függően. Megfelelő mérőtű, akár varrótű alkalmazásával is.

    Az elektronikában a polaritáscsere a legveszélyesebb játékok közé tartozik, tehát a cél szentesíti az eszközt.

    Alábbi idézet, ha nem is rövid, de egy hosszabb oldal minket érdeklő részeit emeltem ki:

    http://en.wikipedia.org/wiki/Universal_Serial_Bus

    Charging ports and accessory charging adapters

    Charging ports exist in two flavors: charging downstream ports (CDP), supporting data transfers as well, and dedicated charging ports (DCP), without data support. A portable device can recognize the type of USB port from the way the D+ and D- pins are connected. For example, on a dedicated charging port, the D+ and D- pins are shorted. With charging downstream ports, current passing through the thin ground wire may interfere with high-speed data signals. Therefore, current draw may not exceed 900 mA during high-speed data transfer. A dedicated charge port may have a rated current between 500 and 1,500 mA. There is no upper limit for the rated current of a charging downstream port, as long as the connector can handle the current (standard USB 2.0 A-connectors are rated at 1.5 A).

    Before the battery charging specification was defined, there was no standardized way for the portable device to inquire how much current was available. For example, Apple's iPod and iPhone chargers indicate the available current by voltages on the D- and D+ lines. When D+ = D- = 2 V, the device may pull up to 500 mA. When D+ = 2.0 V and D- = 2.8 V, the device may pull up to 1 A of current. When D+ = 2.8 V and D- = 2.0 V, the device may pull up to 2 A of current.

    OMTP/GSMA Universal Charging Solution

    On 17 February 2009, the GSM Association (GSMA) announced that they had agreed on a standard charger for mobile phones. The standard connector adopted by manufacturers — including Nokia, Motorola, and Samsung — is the micro-USB connector (several media reports erroneously reported this as the mini-USB). New chargers are to be much more efficient than existing chargers.

    http://ec.europa.eu/enterprise/sectors/rtte/files/chargers/chargers_annex_ii_to_mou_january_12_2010_en.pdf

    7. Adapter Detection

    As per: USB Battery Charging Specification, Revision 1.1 (BC 1.1), Section 4.1 Charging Port. EPS shall meet the USB-IF Charging Port Test Requirements for a Dedicated Charging Port. Top level requirements listed below:

    • The EPS shall short the D+ and D- lines with a resistance not greater than 200 ohms.
    • The resistance between the D+ or D- lines of the EPS and either Vbus or Gnd shall be greater than 2 MOhms.
    • The capacitance between the D+ or D- lines of the EPS and either Vbus or Gnd shall be less than 1nF.

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    Itt az utolsó két pontot nyilván csak a rend kedvéért másoltam át, gyakorlat szempontjából az első pont a lényeg.

    [ Szerkesztve ]

    Ahol trollok hangja többet ér, ahol a kiskirály, mint kutyával beszél? A fórum szakmai támogatását befejeztem.

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