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

Carlos Camargo cicamargoba at gmail.com
Fri Jul 30 12:01:08 EDT 2010


[1]http://arduino.cc/en/Main/ArduinoBoardDuemilanove

We will ti use a similar design for +5V collide protection. But this circuit
has problems with low level voltages, under 5V

Carlos



On Fri, Jul 30, 2010 at 10:50 AM, David Reyes Samblas Martinez <
david at tuxbrain.com> wrote:

> I forget to add the link.
>
> 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
> >>> > 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!!!
> >>>
> >>> _______________________________________________
> >>> 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!!!
>
> _______________________________________________
> 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
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