Re: Minty Boost FreeRunner
Am Fr 21. November 2008 schrieb Tobias Diedrich: Cédric Berger wrote: On Thu, Nov 20, 2008 at 17:24, DJDAS [EMAIL PROTECTED] wrote: Cédric Berger ha scritto: I did not have a look at neo's circuitry. But whatever the method it uses, it cannot force 1A if 1A is not available (wall charger unplugged from the wall won't give 1A :-p ) ? Uhm...not exactly true... Ohm Law says: V = R * I - I = V/R, and if R-0 then I-oo In practice if you power a load with a little impedance (in real systems the load is not always only resistive) the current requested will grow and the source could be damaged (try to short circuit a normal battery, you'll see a flash and if you maintain the circuit closed you'll meld the battery). This is why you should not ask 1000mA from the USB port (for example) unless you're sure the hardware could give it. Bye :) Yes but I also have some car adapters that did not mind being shorted (12v to 5v adapter, given for 350mA). So I doubt a device wanting 1A would be worst than a short circuit... but what would be the output in such a case I do not know. According to the MAX756 datasheet (the step-up converter used in the minty boost AFAICS), the switching mosfet should be protected due to the operating principle: The coil is shorted to ground until the current reaches about 1A, then switched off automatically (and then the coil discharges in series to the battery, effectively boosting the voltages). So the only things relevant to a overload situation are the coil rating and the diode rating. If both are capable of handling 1A continously, then switching the Freerunner to 1A can't break anything. The 1N5818 can handle 1A and the coil used has a saturation current of 1.5A. (However, it is _not_ short-circuit-proof, since in that case the current would flow directly from the battery over coil and diode to ground and will likely destroy the diode first) Switching noise is nothing to worry about (Switching frequency depends on load and battery voltage). Of course thermal dissipation can still be an issue. you should use a polyfuse, to make device resistant against short on output /j signature.asc Description: This is a digitally signed message part. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
El día Monday, September 29, 2008 a las 10:17:49AM +0200, Matthias Apitz escribió: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... It seems that here in Germany they don't sell this type of Chewing Gum boxes, the boxes here have other length and width, bigger in width but maybe shorter in length; could someone mail me please the values of length and width in millimeter of the original box to see if the batteries will fit; Hello, A colleague of me was kind enough to build that MintyBoost for me. And it is working fine. I'm attaching a screen shoot of it using 'battery.py'; some questions remain: - sometimes you can hear in the MintyBoost box (not in the FR) some kind of buzzing, is this normal? - sometimes the chip and the electromagnetic coil get very hot, sometimes only warm, anything to worry about? - if the FR battery gets charged by the MintyBoost, the MintyBoost at the same time has also to provide the energy for the running FR, correct? Thx matthias -- Matthias Apitz Manager Technical Support - OCLC GmbH Gruenwalder Weg 28g - 82041 Oberhaching - Germany t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e [EMAIL PROTECTED] - w http://www.oclc.org/ http://www.UnixArea.de/ b http://gurucubano.blogspot.com/ Q: What's the difference between an iphone and a freerunner? A: One works but takes away your freedom, the other is free but needs your work. attachment: mintyCharging.jpg___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... Shouldn't it be easy to add this 'wall charger indicator resistor' to the mintyboost circuit? I don't remember where that resistor needs to go, but this can be researched on the wiki... -- Drucken Sie diese Mail bitte nur auf Recyclingpapier aus. Please print this mail only on recycled paper. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
El día Thursday, November 20, 2008 a las 01:47:43PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... Shouldn't it be easy to add this 'wall charger indicator resistor' to the mintyboost circuit? I don't remember where that resistor needs to go, but this can be researched on the wiki... What would be the bennefit of this? I'm not an electronic guy anymore :-( matthias -- Matthias Apitz Manager Technical Support - OCLC GmbH Gruenwalder Weg 28g - 82041 Oberhaching - Germany t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e [EMAIL PROTECTED] - w http://www.oclc.org/ http://www.UnixArea.de/ b http://gurucubano.blogspot.com/ Q: What's the difference between an iphone and a freerunner? A: One works but takes away your freedom, the other is free but needs your work. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Matthias Apitz wrote: El día Thursday, November 20, 2008 a las 01:47:43PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... Shouldn't it be easy to add this 'wall charger indicator resistor' to the mintyboost circuit? I don't remember where that resistor needs to go, but this can be researched on the wiki... What would be the bennefit of this? I'm not an electronic guy anymore :-( 1A charging out of the box with no software needed. -- Drucken Sie diese Mail bitte nur auf Recyclingpapier aus. Please print this mail only on recycled paper. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
El día Thursday, November 20, 2008 a las 02:04:22PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Thursday, November 20, 2008 a las 01:47:43PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... Shouldn't it be easy to add this 'wall charger indicator resistor' to the mintyboost circuit? I don't remember where that resistor needs to go, but this can be researched on the wiki... What would be the bennefit of this? I'm not an electronic guy anymore :-( 1A charging out of the box with no software needed. Here is what the Wiki page says: http://wiki.openmoko.org/wiki/Neo_FreeRunner_Battery «DIY external battery pack from a Minty case Mintyboost: Charge from a couple of AA batteries: Minty Boost!, report on a Neo FreeRunner application. Adding the 47k resistor to the minty boost so that the Freerunner fast charges at 1A is a poor idea for a couple reasons, the biggest one being that the minty boost can't supply 1A the max is 600mA. as far as I know, there is no magic resistor to identify a 500mA charger to the Freerunner, it depends on USB host telling it that it can provide 500mA. Second, the ID pin is in the USB micro connector, so you would either need to put a micro connector on your minty boost (with the correct resistor installed) or use a hacked cable. Even if the Linear Technology step up voltage converter is supposed to be able to do 600mA, the AA cells seem to have a problem with supplying 500mA. They get a little toasty :-). One powerpack built using D cells doesn't seem to have any issues with supplying 500mA.» My FR switches outomagically to 1A charging mode, but maybe it's better to only use 500mA matthias -- Matthias Apitz Manager Technical Support - OCLC GmbH Gruenwalder Weg 28g - 82041 Oberhaching - Germany t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e [EMAIL PROTECTED] - w http://www.oclc.org/ http://www.UnixArea.de/ b http://gurucubano.blogspot.com/ Q: What's the difference between an iphone and a freerunner? A: One works but takes away your freedom, the other is free but needs your work. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Matthias Apitz wrote: El día Thursday, November 20, 2008 a las 02:04:22PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Thursday, November 20, 2008 a las 01:47:43PM +0100, Tilman Baumann escribió: Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... Shouldn't it be easy to add this 'wall charger indicator resistor' to the mintyboost circuit? I don't remember where that resistor needs to go, but this can be researched on the wiki... What would be the bennefit of this? I'm not an electronic guy anymore :-( 1A charging out of the box with no software needed. Here is what the Wiki page says: http://wiki.openmoko.org/wiki/Neo_FreeRunner_Battery «DIY external battery pack from a Minty case Mintyboost: Charge from a couple of AA batteries: Minty Boost!, report on a Neo FreeRunner application. Adding the 47k resistor to the minty boost so that the Freerunner fast charges at 1A is a poor idea for a couple reasons, the biggest one being that the minty boost can't supply 1A the max is 600mA. Ups, that's a pitty. I did not anticipate this. Even if the Linear Technology step up voltage converter is supposed to be able to do 600mA, the AA cells seem to have a problem with supplying 500mA. They get a little toasty :-). One powerpack built using D cells doesn't seem to have any issues with supplying 500mA.» Well, Batteries usually put out a great much of current without suffering too much. I could not find any specifications (which of course vary) on a short notice, but I don't think that 5W (plus a little bit loss in the converter) is too much. Maybe we just need to make a heavy duty mintyboost with a bigger converter... My FR switches outomagically to 1A charging mode, but maybe it's better to only use 500mA Probably. The reports of hearing the converter when it is under load support this. -- Drucken Sie diese Mail bitte nur auf Recyclingpapier aus. Please print this mail only on recycled paper. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
On Thu, Nov 20, 2008 at 15:14, Matthias Apitz [EMAIL PROTECTED] wrote: Adding the 47k resistor to the minty boost so that the Freerunner fast charges at 1A is a poor idea for a couple reasons, the biggest one being that the minty boost can't supply 1A the max is 600mA. as far as I know, there is no magic resistor to identify a 500mA charger to the Freerunner, it depends on USB host telling it that it can provide 500mA. Yes 1A is a lot. I am not an electronician but would not it be possible to have a little circuit in the minty boost limiting current to 500mA (or other value), even though the freerunner tries to get 1A ? ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Cédric Berger wrote: On Thu, Nov 20, 2008 at 15:14, Matthias Apitz [EMAIL PROTECTED] wrote: Adding the 47k resistor to the minty boost so that the Freerunner fast charges at 1A is a poor idea for a couple reasons, the biggest one being that the minty boost can't supply 1A the max is 600mA. as far as I know, there is no magic resistor to identify a 500mA charger to the Freerunner, it depends on USB host telling it that it can provide 500mA. Yes 1A is a lot. I am not an electronician but would not it be possible to have a little circuit in the minty boost limiting current to 500mA (or other value), even though the freerunner tries to get 1A ? Nope. Current is a effect not a cause. *g* -- Drucken Sie diese Mail bitte nur auf Recyclingpapier aus. Please print this mail only on recycled paper. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Matthias Apitz wrote:
Hello,
A colleague of me was kind enough to build that MintyBoost for me. And
it is working fine. I'm attaching a screen shoot of it using
'battery.py'; some questions remain:
- sometimes you can hear in the MintyBoost box (not in the FR) some kind
of buzzing, is this normal?
According to the MintyBoost FAQ
http://www.ladyada.net/make/mintyboost/faq.html
{ When I plug in a device, sometimes theres a 'hum', 'hiss', 'squeak',
{ 'whine', etc noise...is this normal?
{
{ Yes, sometimes the inductor resonates with the boost converter and
{ that resonance leaks into the audible range. While it's not good for
{ it to always vibrate, it does happen occasionally and is not harmful
{ to the charging device. you can try moving the inductor a little with
{ your finger but the noise is electrical in nature so its hard to stop
{ completely.
{
{ Another thing is that it depends on how much power the device is
{ drawing and what kind of batteries are inside.
- sometimes the chip and the electromagnetic coil get very hot,
sometimes only warm, anything to worry about?
Again, from the FAQ
{ When I use the kit, the chip/batteries seems warm...Is this OK?
{ Its normal for the chip and batteries to be warm or a little hot,
{ especially when charging a device that is nearly drained. The chip
{ should not get hot or very warm when nothing is plugged in.
{
{ However, if the batteries/chip are so hot that its painful to touch,
{ start to smoke, or melt or leak fluidsomething is wrong! :)
Also, your screenshot indicated you are charging at 1A, the step up
voltage converter in the MintyBoost is only capable of 600mA, so that
could explain some of the excess heat and noise.
- if the FR battery gets charged by the MintyBoost, the MintyBoost at
the same time has also to provide the energy for the running FR, correct?
My understanding of the power system on the FR is that some components
draw their power only from the battery even when an external power
source is available. But I am sure there are others on the list with a
more complete understanding of the power system.
-stacy
___
Openmoko community mailing list
community@lists.openmoko.org
http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
On Thu, Nov 20, 2008 at 16:10, Tilman Baumann [EMAIL PROTECTED] wrote: Cédric Berger wrote: I am not an electronician but would not it be possible to have a little circuit in the minty boost limiting current to 500mA (or other value), even though the freerunner tries to get 1A ? Nope. Current is a effect not a cause. *g* -- I did not have a look at neo's circuitry. But whatever the method it uses, it cannot force 1A if 1A is not available (wall charger unplugged from the wall won't give 1A :-p ) ? Probably the voltage will have to be dropped so that less current (and/or power) is given to Neo... remains to be seen to what point this can (?) be done with the neo still accepting charging ? ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Cédric Berger ha scritto: I did not have a look at neo's circuitry. But whatever the method it uses, it cannot force 1A if 1A is not available (wall charger unplugged from the wall won't give 1A :-p ) ? Uhm...not exactly true... Ohm Law says: V = R * I - I = V/R, and if R-0 then I-oo In practice if you power a load with a little impedance (in real systems the load is not always only resistive) the current requested will grow and the source could be damaged (try to short circuit a normal battery, you'll see a flash and if you maintain the circuit closed you'll meld the battery). This is why you should not ask 1000mA from the USB port (for example) unless you're sure the hardware could give it. Bye :) ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
On Thu, Nov 20, 2008 at 17:24, DJDAS [EMAIL PROTECTED] wrote: Cédric Berger ha scritto: I did not have a look at neo's circuitry. But whatever the method it uses, it cannot force 1A if 1A is not available (wall charger unplugged from the wall won't give 1A :-p ) ? Uhm...not exactly true... Ohm Law says: V = R * I - I = V/R, and if R-0 then I-oo In practice if you power a load with a little impedance (in real systems the load is not always only resistive) the current requested will grow and the source could be damaged (try to short circuit a normal battery, you'll see a flash and if you maintain the circuit closed you'll meld the battery). This is why you should not ask 1000mA from the USB port (for example) unless you're sure the hardware could give it. Bye :) Yes but I also have some car adapters that did not mind being shorted (12v to 5v adapter, given for 350mA). So I doubt a device wanting 1A would be worst than a short circuit... but what would be the output in such a case I do not know. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Cédric Berger wrote: On Thu, Nov 20, 2008 at 17:24, DJDAS [EMAIL PROTECTED] wrote: Cédric Berger ha scritto: I did not have a look at neo's circuitry. But whatever the method it uses, it cannot force 1A if 1A is not available (wall charger unplugged from the wall won't give 1A :-p ) ? Uhm...not exactly true... Ohm Law says: V = R * I - I = V/R, and if R-0 then I-oo In practice if you power a load with a little impedance (in real systems the load is not always only resistive) the current requested will grow and the source could be damaged (try to short circuit a normal battery, you'll see a flash and if you maintain the circuit closed you'll meld the battery). This is why you should not ask 1000mA from the USB port (for example) unless you're sure the hardware could give it. Bye :) Yes but I also have some car adapters that did not mind being shorted (12v to 5v adapter, given for 350mA). So I doubt a device wanting 1A would be worst than a short circuit... but what would be the output in such a case I do not know. According to the MAX756 datasheet (the step-up converter used in the minty boost AFAICS), the switching mosfet should be protected due to the operating principle: The coil is shorted to ground until the current reaches about 1A, then switched off automatically (and then the coil discharges in series to the battery, effectively boosting the voltages). So the only things relevant to a overload situation are the coil rating and the diode rating. If both are capable of handling 1A continously, then switching the Freerunner to 1A can't break anything. The 1N5818 can handle 1A and the coil used has a saturation current of 1.5A. (However, it is _not_ short-circuit-proof, since in that case the current would flow directly from the battery over coil and diode to ground and will likely destroy the diode first) Switching noise is nothing to worry about (Switching frequency depends on load and battery voltage). Of course thermal dissipation can still be an issue. HTH, -- Tobias PGP: http://9ac7e0bc.uguu.de このメールは十割再利用されたビットで作られています。 ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Matthias Apitz wrote: It seems that here in Germany they don't sell this type of Chewing Gum boxes, I had a hard time finding it locally as well. I finally mail ordered a ten pack. On the plus side, the gum doesn't stick to my dental work, so I can actually chew the stuff. the boxes here have other length and width, bigger in width but maybe shorter in length; could someone mail me please the values of length and width in millimeter of the original box to see if the batteries will fit; in mm, 82.5 x 34.0 x 18.5 (L x W X H) On the subject of boxes can anyone suggest an interesting container that would hold a pair of D cells with a little room (20mm x 34mm) to spare for the boost pcb? -stacy ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... It seems that here in Germany they don't sell this type of Chewing Gum boxes, the boxes here have other length and width, bigger in width but maybe shorter in length; could someone mail me please the values of length and width in millimeter of the original box to see if the batteries will fit; thx in advance matthias -- Matthias Apitz Manager Technical Support - OCLC GmbH Gruenwalder Weg 28g - 82041 Oberhaching - Germany t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e [EMAIL PROTECTED] - w http://www.oclc.org/ http://www.UnixArea.de/ b http://gurucubano.blogspot.com/ A computer is like an air conditioner, it stops working when you open Windows Una computadora es como aire acondicionado, deja de funcionar si abres Windows ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
Why not just measure the batteries yourself? It's just two AA cells where one cell is 50mm height and 14mm diameter. Than you add the space you need for the little step-up converter and that's all. Ciao, Rainer Matthias Apitz wrote: El día Monday, September 22, 2008 a las 11:17:58PM +0200, Matthias Apitz escribió: Hello Stacy, I've stumbled over your page http://www.millions.ca/~stacy/mintyboost/ and as an owner of the FreeRunner I will build this nice box; thanks for your pioneer work on this; ... It seems that here in Germany they don't sell this type of Chewing Gum boxes, the boxes here have other length and width, bigger in width but maybe shorter in length; could someone mail me please the values of length and width in millimeter of the original box to see if the batteries will fit; thx in advance matthias ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: Minty Boost FreeRunner
El día Monday, September 29, 2008 a las 11:11:04AM +0200, Fox Mulder escribió: Why not just measure the batteries yourself? It's just two AA cells where one cell is 50mm height and 14mm diameter. Than you add the space you need for the little step-up converter and that's all. Ofc I can measure the two AA cells by my own, but not the rest (the space for the platine of the converter and the USB connector); that's why I was asking for the size of the original box because in this it fits; thx for your feedback anyway (and don't top post :-)) matthias -- Matthias Apitz Manager Technical Support - OCLC GmbH Gruenwalder Weg 28g - 82041 Oberhaching - Germany t +49-89-61308 351 - f +49-89-61308 399 - m +49-170-4527211 e [EMAIL PROTECTED] - w http://www.oclc.org/ http://www.UnixArea.de/ b http://gurucubano.blogspot.com/ A computer is like an air conditioner, it stops working when you open Windows Una computadora es como aire acondicionado, deja de funcionar si abres Windows ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
