#qi-hardware IRC log for Sunday, 2015-01-18

--- Sun Jan 18 201500:00
arossdotmeis there a single component thats like a diode but with out the loss? need a way of stoping a li batt being charged by the device it's connected too becuase i have a faster charged connected to it instead but i want the device to monitor the batt level so i know how much is left  roughly and can power off when the bat is low.01:04
whitequarkschottky diode has a voltage drop of 0.1-0.2V01:08
whitequarkgood ones even 0.0501:08
whitequarkhm, apparently diodes with Vf<0.22 do not exist01:10
arossdotmewhat about these mosfets? a combined with schottky diode?01:13
arossdotmeor something?01:13
arossdotmei'm having a look at how the nano note does it and is that how?01:13
arossdotmebtw the soultuion needs to take around 1A01:14
whitequarkusually a schottky is used for this purpose01:15
arossdotmea all in one component as it's attractions thats all01:15
arossdotmeschottky with nothing else?01:16
whitequarkwhy not01:16
arossdotmeidk :)01:17
arossdotmeefficacy, 01:17
arossdotmebadly spelled 01:17
arossdotmeefficiency 01:17
arossdotmei find it surprising01:17
arossdotmeand what about a usb 5v 500ma,1A,2A load?01:18
arossdotmewith a..01:18
arossdotmestill a schottky?01:19
arossdotmethanks for you input01:29
nicksydneywpwrak: http://www.cnx-software.com/2015/01/18/one-dollar-development-board/ :)07:44
whitequarkmeh. stm807:45
nicksydneywhitequark: yeah it's only stm8 ...i think the price point is what attractive ...but the tools is not attractive07:55
wpwrakrubbish. those phones are not detectors. they're GENERATORS. generators of evil deadly cosmic rays. SCIENTIFIC FACT: the number of DEATHS, globally, has INCREASED since the widespread use of mobile phones, around 2000, to today. DESPITE mortality in general having decreased thanks to better medicine, etc.12:23
wpwrakscience doesn't lie. there is a murderous conspiracy behind mobile phones, driven by corporate greed !12:24
larscdriven by the soylent green industry13:19
wpwrakthe soylent-nestle global conglomerate !13:21
eintopfwin 918:06
eintopfsorry :-)18:06
larscwin 9 is ok, what scares me are the people wo type e.g. 'win 74'18:11
ysionneauI do :p18:33
DocScrutinizer05arossdotme: (diode w/o loss) there are "ideal diode" components made of mosfet18:40
DocScrutinizer05arossdotme: 2nd hit on google http://www.linear.com/product/LTC435818:43
DocScrutinizer05there are a lot others with different specs18:44
DocScrutinizer05arossdotme: this might be almost what you asked for: http://cds.linear.com/docs/en/datasheet/4412hvfs.pdf19:06
arossdotmethx, i'll have a look19:07
DocScrutinizer05depending on your requirements a component like http://www.ti.com/lit/ds/symlink/tps2104.pdf might even be better suited19:12
arossdotmemy requirements are: that it's compact and self contained and preferably doesn't need external components as it's being wired inbetween things/modules. 19:18
arossdotmeit's being used for...19:19
arossdotmepreventing the device (a #zipit ) from charging my external 6600mah li batt that has it's own 1A charger. the zipit is connect to directly to the battery so the zipit is more efficiently powered and also i can use it's battery monitoring19:22
arossdotme(btw if you know of a small compact faster charger for a 6600mah li batt i'd like to know :) )19:22
arossdotmei'm not sure about this but to stop my external usb power boost which powers the usb hub from powering the zipit as the exteral mains/car power supply to charge the battery and power the zipit while pluged in, is also connected to the usb hub in parallel with the usb boost19:27
arossdotme- to stop the usb boost feeding into the dc_in of the zipit and the mains pwr supply feeding into the ower boost but is that a problem in the first place? idk19:29
arossdotmeI'm also planning to use this with my gta04 when it comes in the post :D19:30
arossdotmeso i hope that illustrates my usage case19:30
arossdotmebut you have been a huge help with giving me "ideal diode"19:31
arossdotmei'll be busy trying to work out which one to go for... hmmmmmm19:31
arossdotmeoh so it's 1A+/- for the usb boost and less then 500ma for the zipit19:39
arossdotmeso i'm not sure if your last one is suited current wise?19:39
DocScrutinizer05are you sure that's not a class-XY problem? Anyway I fail to get the jigsaw puzzle assembled to form a picture of what you're planning to do19:39
DocScrutinizer05aiui you use some device "zipit" unknown, an external USB battery pack, a USB hub, and internal battery in zipit? auxiliary power from car 12V? even 2 hubs? sorry you lost me19:42
DocScrutinizer05maybe a sketch would help a lot19:42
arossdotme yea thought i might need to draw it :019:44
arossdotmearr i meen :) not :019:44
DocScrutinizer05anyway external USB battery packs commonly use different connections for supplying power and for themselves getting charged 19:45
arossdotmethe point of this is to make a DIY usb batt pack with some extra advantages19:46
DocScrutinizer05USB hubs are supposed to feed trough VBUS supply form uplink (to host) to the N downlink ports, but usually not the inverse direction. They also are supposed to not feed aux power from a PSU to the uplink port19:46
arossdotme /using my exisiting spear batt19:46
DocScrutinizer05I however think there are a few USB hubs with built-in battery, maybe that's a useful alternative, replacing the internal battery by your external spare batt20:03
arossdotmeooooe usb hub with built in batt, theres a thought20:21
arossdotmebut i alreadly have this big batt waiting to be put to use :)20:21
arossdotmeheres a drawing20:22
arossdotmeDocScrutinizer05, https://filetea.me/t1sf2Bh6pXfTxCufX8M2zKWgQ20:22
arossdotmeoh yea no zipit batt, its dead20:37
DocScrutinizer05looks overly complicated. zipit already has a LiIon charger (bq24032?)21:01
DocScrutinizer05why use a discrete one?21:02
DocScrutinizer05dang, bq2403521:03
arossdotmefaster charge rate, sas told with my size batt it night not even manage to charge it fully21:04
arossdotmewhen being used with gta04 it can charge on its own21:05
arossdotmethat is to say its standalone21:05
DocScrutinizer05well, I doubt the "can't charge to full" is any correct21:07
DocScrutinizer05tbh even when I'd plan for all the function blocks you did, I'd simply use a 2-throw relay to switch between operation modes, rather than ideal diodes21:11
DocScrutinizer05powering battery contacts of a BQ24035 device from a LiIon via an ideal diode won't pan out21:16
DocScrutinizer05in device aux-powered mode21:16
DocScrutinizer05BQ24035 will try to charge and only see the diode21:17
DocScrutinizer05either you conect the battery as supposed to (directly), or not at all21:17
DocScrutinizer05why do you need the USB booster for hub? doesn't zipit provide VBUS?21:19
DocScrutinizer05btw http://www.ti.com/lit/ds/symlink/bq24035.pdf says the battery charge current can go as high as 1500mA. I'd think that's sufficient for most fastcharging purposes21:28
DocScrutinizer05alternatively you can operate the zipit from battery only, even while battery gets charged by external charger circuit. No need to power the zipit from AC in during charging battery like that21:30
arossdotmea relay! but the power consumption... isn't it a lot?21:50
arossdotmeadmittedly it bugged me "can't charge to full" ,thought it sounded odd, thx for your input21:51
arossdotmere usb booster is needed as the zipit does not have a 5v our unless it's pluged into aux pwr or a 3.3v to 5V converter is used but max 300ma current out. which is not enough for the semi pro usb audio interface i want to run from it. gta04 also has a max of 100ma21:54
arossdotmere "bq24035  says the battery charge current can go as high as 1500mA" i assumed in the zipit it's not programmed to do that. the original batt was 1200mah. it does have a 3rd wire which i assume is a thermomistor21:57
arossdotmeDocScrutinizer05, hmm lots to think about... thx again for you input as always. maybe i sound do some tests with the zipit charger to see how much  current it charges with...22:01
arossdotmeok relay not such a issue as it's only when pluged into mains but for the fact it interpts the zipit as it loses pwr22:07
arossdotme" it does have a 3rd wire which i assume is a thermomistor"=  it does have a 3rd wire which looks like a thermomistor22:10
arossdotmemeasured with test meter22:11
qi-bot[commit] Werner Almesberger: slicer/slicer.c: rewrite - we now consider all non-horizontal facets (master) http://qi-hw.com/p/cae-tools/005dcc323:30
qi-bot[commit] Werner Almesberger: cameo/area-poly2d.c (area): fail if any paths are open (master) http://qi-hw.com/p/cae-tools/4d1595123:30
qi-bot[commit] Werner Almesberger: cameo/poly2d.c (paths_to_polys_z): correctly ignore empty paths (master) http://qi-hw.com/p/cae-tools/c9c0e8823:30
qi-bot[commit] Werner Almesberger: cameo/path.c (path_connect, et al.): move to new file connect.c (master) http://qi-hw.com/p/cae-tools/f94fb2f23:30
qi-bot[commit] Werner Almesberger: poly2d/p2d_attrib.c (p2d_no_intersect): don't test last vs. first segment (master) http://qi-hw.com/p/cae-tools/84f9d3c23:30
qi-bot[commit] Werner Almesberger: poly2d/p2d_area_holes.cpp (recurse_area): correct confusing indentation (master) http://qi-hw.com/p/cae-tools/6084b5223:30
qi-bot[commit] Werner Almesberger: poly2d/p2d_attrib.c (angle_3): put spaces around operators (master) http://qi-hw.com/p/cae-tools/de7df0b23:30
qi-bot[commit] Werner Almesberger: poly2d/p2d_attrib.c: correct line wrap in title comment (how did this get there ?) (master) http://qi-hw.com/p/cae-tools/05d3d5023:30
qi-bot[commit] Werner Almesberger: poly2d/p2d_attrib.c (angle_3): don't divide by zero ... (master) http://qi-hw.com/p/cae-tools/7ca942d23:30
wpwrakdebugging geometry problems is hell :-(23:30
--- Mon Jan 19 201500:00

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