Power from USB & DC Adapter (was Re: Design Files/Gerbers of SAKC V2)

David Reyes Samblas Martinez david at tuxbrain.com
Fri Jul 30 11:50:18 EDT 2010


I forget to add the link.
[1]http://arduino.cc/en/Main/ArduinoBoardDuemilanove

2010/7/30 David Reyes Samblas Martinez <david at tuxbrain.com>:
> 2010/7/30 Carlos Camargo <cicamargoba at gmail.com>:
>
>> Arduino for example, works with 5V,
> Wrong, the most common board "duemilanove":
> from his specification page[1]
> Operating Voltage       5V
> Input Voltage (recommended)     7-12V
> Input Voltage (limits)  6-20V
>
> it only use 5V as input when powered though USB,
>
> I you have a 5V power source you can use the USB plug to avoid the 6V
> input limitation on Vin,
>
>
>> I think that the daughter card will have the specific power supply, so we
>> can reduce the SAKC complexity and maintain the flexibility.
> ok I can agree in fact "low" voltage from higher to 5V is no a big
> deal, a voltage regulator before the plug can fit for an especific
> aplication. rising voltage is allways more complicated.
>>
>>
>> Carlos
>>
>>
>>
>> On Fri, Jul 30, 2010 at 10:17 AM, David Reyes Samblas Martinez
>> <david at tuxbrain.com> wrote:
>>>
>>> I must agree with Ron that we don't have to save in "poka yokes" on
>>> the power sourcing on SACK
>>> +1 to the  +/- protection
>>> +1 to the +5V collide protection
>>>
>>> and how much cost and space is for the power regulator?
>>>
>>> 2010/7/30 Ron K. Jeffries <rjeffries at gmail.com>:
>>> > Please make sure that the design protects
>>> > against plus and minus being plugged in wrong.
>>> > I think that implies a zener diode.
>>> > the extra cost of a 5V supply that accepts a fairly
>>> > wide range of input voltage say 12v or less
>>> > is probably worth it IMO
>>> > SAKC is prolly less price sensitive than Nanonote.
>>> > ---
>>> > Ron K. Jeffries
>>> > http://ronkjeffries.posterous.com
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > On Fri, Jul 30, 2010 at 07:44, Carlos Camargo <cicamargoba at gmail.com>
>>> > wrote:
>>> >>
>>> >> Hi Adam
>>> >>
>>> >>
>>> >>
>>> >> On Fri, Jul 30, 2010 at 8:53 AM, Adam Wang <adam at sharism.cc> wrote:
>>> >>>
>>> >>> Hi,
>>> >>>
>>> >>> 1, I made a mistake on D10 footprint confirmation, It must be 0805 to
>>> >>> meet MSCD104H. Pls change this to 0805 package.
>>> >>
>>> >> ok, I'll fix it
>>> >>
>>> >>
>>> >>>
>>> >>> 2, maybe mark a concentric circles with central ring to mark "+" and
>>> >>> outer ring marked a "-" nearby DC Jack to suffer from mistakes by
>>> >>> novices.
>>> >>
>>> >> Agree
>>> >>
>>> >>>
>>> >>> 3, last but not least, current design of SAKC V2 have a condition that
>>> >>> is
>>> >>> it can not use +5V power at the same time either from USB cable
>>> >>> (0.5A) or DC
>>> >>> adapter(can be more). If using DC adapter fixed +5V in already,
>>> >>> you must _remember_ to take out mini-jumper on J18 first, then plug-in
>>> >>> usb
>>> >>> cable to do s/w work. If you forgot that take out mini-jumper, after
>>> >>> plugging usb cable; There must be have power +5V "collide" together.
>>> >>> This
>>> >>> UNSAFE condition will be happened once mindless to forget to take out
>>> >>> mini-jumper. And possibly let USB host device to be have damage or
>>> >>> even DC
>>> >>> adapter source. Also if remove DC adapter, the SAKC it can only get
>>> >>> 0.5A
>>> >>> from usb, unworthy a bit. so
>>> >>>
>>> >>> 1) remove the DC adapter reducing the hardware hacking usability of
>>> >>> the
>>> >>> board a lot.
>>> >>
>>> >>
>>> >>>
>>> >>> 2) remove USB power, adding the need for an extra power adapter for
>>> >>> every
>>> >>> user.
>>> >>
>>> >>
>>> >>>
>>> >>> 3) add additional circuitry to make both USB & DC power stable in all
>>> >>> cases. User should have the chance to update s/w from USB while still
>>> >>> some
>>> >>> h/w parts connected to SAKC board's extendable 40pins header to get
>>> >>> 3.3V
>>> >>> supply( actually comes from 5V) to outside application.
>>> >>
>>> >> Yes, I'm trying to solve this issue, I think that we can use a single
>>> >> circuit Power On Reset + Transistor:
>>> >>                             TRANSISTOR
>>> >> USB_VCC-------------|S|           |D|----------- 5V
>>> >>                                                        |
>>> >>                                      |G|              |
>>> >>                                        |               |
>>> >> DC_WALL------|  POR |----------------------
>>> >>
>>> >>
>>> >> When DC_WALL = 0V  Transistor is ON so 5V = USB_VCC
>>> >> when DC_WALL >= POR's threshold => Transistor is OFF =>  5V = DC_WALL
>>> >>
>>> >>>
>>> >>> Also if SAKC comes with capability of having strong wide power range
>>> >>> input, this can make/let additional circuities connected to SAKC
>>> >>> easiler and
>>> >>> more flexible with ONLY one DC adapter. Fg. real ROBOT industries
>>> >>> works
>>> >>> around +12V or +9V supply. IMO if this can be true. SAKC will be more
>>> >>> stronger. Surely aside from cost evaluation.
>>> >>
>>> >> We can't provide all the possible voltages for all the possible
>>> >> applications. We can add an additional 5v regulator with a wide input
>>> >> range,
>>> >> but this increase the cost & the size.
>>> >> Carlos
>>> >>
>>> >>
>>> >> --
>>> >> Carlos Iván Camargo Bareño
>>> >> Profesor Asistente
>>> >> Departamento de Ingeniería Eléctrica y Electrónica
>>> >> Universidad Nacional de Colombia
>>> >> cicamargoba at unal.edu.co
>>> >>
>>> >> _______________________________________________
>>> >> Qi Developer Mailing List
>>> >> Mail to list (members only): developer at lists.qi-hardware.com
>>> >> Subscribe or Unsubscribe:
>>> >> http://en.qi-hardware.com/mailman/listinfo/developer
>>> >
>>> >
>>> > _______________________________________________
>>> > Qi Developer Mailing List
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>>> > Subscribe or Unsubscribe:
>>> > http://en.qi-hardware.com/mailman/listinfo/developer
>>> >
>>>
>>>
>>>
>>> --
>>> David Reyes Samblas Martinez
>>> http://www.tuxbrain.com
>>> Open ultraportable & embedded solutions
>>> Ben NanoNote, Arduino, Openmoko
>>> Hey, watch out!!! There's a linux in your pocket!!!
>>>
>>> _______________________________________________
>>> Qi Developer Mailing List
>>> Mail to list (members only): developer at lists.qi-hardware.com
>>> Subscribe or Unsubscribe:
>>> http://en.qi-hardware.com/mailman/listinfo/developer
>>
>>
>>
>> --
>> Carlos Iván Camargo Bareño
>> Profesor Asistente
>> Departamento de Ingeniería Eléctrica y Electrónica
>> Universidad Nacional de Colombia
>> cicamargoba at unal.edu.co
>>
>> _______________________________________________
>> Qi Developer Mailing List
>> Mail to list (members only): developer at lists.qi-hardware.com
>> Subscribe or Unsubscribe:
>> http://en.qi-hardware.com/mailman/listinfo/developer
>>
>
>
>
> --
> David Reyes Samblas Martinez
> http://www.tuxbrain.com
> Open ultraportable & embedded solutions
> Ben NanoNote, Arduino, Openmoko
> Hey, watch out!!! There's a linux in your pocket!!!
>



-- 
David Reyes Samblas Martinez
http://www.tuxbrain.com
Open ultraportable & embedded solutions
Ben NanoNote, Arduino, Openmoko
Hey, watch out!!! There's a linux in your pocket!!!




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