jadi pin d + dan d - di short kan (di sambung kan) gitu ? ga konsleting ?

aku perna mainin ini usb pin utk power external modem gsm ku yg lama, karena
batre nya gembung ... tp kalo di short in ...
bisa kasih foto2 percobaan mas rizki ? kita main rame2 :) bahas rame2 ...



On Mon, Mar 7, 2011 at 12:07 PM, Rizki Pratama <[email protected]>wrote:

> Mau share aja sedikit pengalaman. Saya punya beberapa charger 1A(battery
> box, Car Charger) tapi herannya kenapa nggak satupun mau cas diatas 500ma
> seperti charger asli bawaan HTC yang biasa dicolok ke dinding padahal sama2
> USB port. Nah ternyata kalau HH mengira kita menghubungkannya ke usb port di
> komputer dia hanya slow charge (sekitar 100-250ma) walaupun dicas
> menggunakan charger USB 1A. Karena heran kemudian saya baca ini USB
> Spesification<http://www.usb.org/developers/devclass_docs/Battery_Charging_V1_2.zip>
>
> Kemudian ini yang saya dapatkan (saya quote):
>
> Pertama saya baca ini dari spesifikasi USB atau ada juga  
> disini<http://en.wikipedia.org/wiki/Universal_Serial_Bus#Power>terutama 
> mengenai cas tablet yang membutuhkan sampe 1.8A dari USB Port untuk
> cas misalnya iPad.
>
> *1.2 Background*
> The USB ports on personal computers are convenient places for Portable
> Devices (PDs) to draw current for charging their batteries. This convenience
> has led to the creation of USB Chargers that simply expose a USB standard-A
> receptacle. This allows PDs to use the same USB cable to charge from either
> a PC or from a USB Charger.
> If a PD is attached to a USB host or hub, then the USB 2.0 specification
> requires that after connecting, a PD must draw less than:
> • 2.5 mA average if the bus is suspended
> • 100 mA if bus is not suspended and not configured
> • 500 mA if bus is not suspended and configured for 500 mA
> If a PD is attached to a Charging Port, (i.e. CDP, DCP, ACA-Dock or ACA),
> then it is allowed to draw IDEV_CHG without having to be configured or
> follow the rules of suspend.
>
> In order for a PD to determine how much current it is allowed to draw from
> an upstream USB port, there need to be mechanisms that allow the PD to
> distinguish between a Standard Downstream Port and a Charging Port. This
> specification defines just such mechanisms.
>
> Kemudian saya lihat solusinya.
>
> *1.4.7 Dedicated Charging Port*
> *A Dedicated Charging Port (DCP) is a downstream port on a device that
> outputs power through a USB connector, but is not capable of enumerating a
> downstream device. A DCP shall source IDCP at an average voltage of VCHG.
> A DCP shall short the D+ line to the D- line.*
>
> Kemudian saya coba. hasilnya bisa dilihat di attachment.  Karena Lithium
> menggunakan algoritma Constant Current/Constant 
> Voltage<http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries>untuk
>  cas maka sebelumnya saya pastikan batre dibawah 50% supaya bisa cas
> dengaan amper maksimum. Hasilnya bisa dilihat di skrinsut. Cas 800ma dan
> 250ma. hmmm....keduanya saya konfirmasi juga di Nexus One.
>
> Mudah2an berguna
>
> Salam
> Rizki
>
>
>
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-- 
===============
Indonesian Android Community,  join:  http://forum.android.or.id

HTC Android Phone with HTC Sense and HTCsense.com 
http://www.htc.com/DesireHD/
---------------------
Unlimited Data XL Mobile Broadband  
http://www.xl.co.id/XLInternet/BroadbandInternet
--------------------
i-gadget Store - BEC Bandung
E-mail: [email protected] Ph. 0812-21111191
--------------------
Toko Gila Original  Surabaya
Email: [email protected]  Ph. (031) 91555898
--------------------
Toko EceranShop - BEC  Bandung
E-mail: [email protected]  Ph. 0815-56599888
--------------------

Aturan Jual/Kloteran ID-Android  http://goo.gl/azW7

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