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Home / Other I-Appliances / Virgin Webplayer Solar powering the WP Thoughts on alternative power for the WP

Solar powering the WP (modified 0 times) Quadrat Profile There is a wealth of info in these posting, thanx all for all your posting! I recently got two WPs on uBid, and am working on getting at least one of them set up as a GPS system in my car. Has anyone looked into alternative power sources for the WP? At the moment I am considering solar. Previoulsy I have used a Fujitsu PenTablet PT510(baterry powered) with an external GPS device (cigarette lighter) but that only has a 100MHz CPU so I haven't even tried to play MP3s on it (which is what i am hoping to do with da WP). My concern is getting power to the unit and dont think i want to go with an inverter (cig. lighter to AC) as 1, it will generate a lot of heat and 2, it will put a serious drain on the battery i am sure. Any thoughts? Any one working on this or something similiar? The Thoughtless 1 ...A questions is never a dumb one the first time you ask it. 05-13-2001 06:34:46

RE:Solar powering the WP (modified 0 times) knarf Profile I'm building a ruggedized, solar-powered Webplayer to take with me on a trip over the Yukon (river in Canada/Alaska). I'm using two Siemens Solar SP-10 (12V 10.5W/each) panels, with one or two 7ah 12V batteries. A switching step-down converter based on a Maxim 724 will turn the 12V from the batteries into 5V suitable for the Webplayer. The efficiency of the step-down converter will be somewhere between 70% and 85% (conservative estimate, probably higher in real life). As the Webplayer takes about 3A full swing, the two panels will be able to power the machine as well as charge the batteries for when the sun goes in hiding. The transformation of the cuddly webplayer into a mean, green, waterproof and possibly bulletproof computing machine is nearly finished, I only have to find some way to get waterproof USB and power connectors... 05-17-2001 16:21:09

RE:Solar powering the WP (modified 0 times) LD37 Profile we must see pictures of this bad boy! 05-17-2001 16:33:46

RE:Solar powering the WP (modified 0 times) davethewave Profile Wow! What are the chances of troubling you for some pics ? My need for the solar power seems embarrassingly silly after reading about your planned adventures - but I would love to be able to use this thing outside, in the park, at the beach - whatever - being able to use it anywhere would be awesome... sounds exciting ! David 05-17-2001 16:34:02

RE:Solar powering the WP (modified 0 times) knarf Profile I'll try to put up some pictures before I leave... But first things first, I have to finish the thing before I can take it along... Some specs: - sheet metal case (used to be part of an army 2-stroke fuel pack) - 6 mm polycarbonate ('lexan') 'screen' - aluminium chassis, doubling as processor cooler - 2 * IBM Travelstar 20GB drives - internal 12V->5V converter based on Max724 - external interfaces: USB, power, audio, modem - IR keyboard - DOC as 'emergency backup OS', it contains a small GNU/Linux installation. I might choose to leave out the DOC and the modem, and go for an external USB modem instead. Anyone know a good place in Vancouver to buy stuff like that? I only need the modem when I find myself in the vicinity of a telephone, so I can put some imagery on the website I'll make for the trip. It will be hosting a webcam which will snap a picture every X seconds and record 'interesting' sound events (hence the two drives, the trip will take about 2.5 months so I need quite a lot of disk space). It runs a slightly modified Debian GNU/Linux 'testing' distribution (currently using the 2.4.4 kernel with some USB patches). Agressive use of APM keeps power consumption down (eg. screen blank after 2 minute, I won't need the screen anyway most of the time. The camera will be mounted on a headband, or just attached to the canoe somewhere, and merrily document the whole trip. So, maybe this weekend for pictures. Maybe not... 05-18-2001 05:40:12

RE:Solar powering the WP (modified 0 times) BigDog Profile | Email Now if I got to go to Yukon, the last thing I would take is a computer! Don't you sometimes just want to get away from it all ?? 05-18-2001 09:44:16

RE:Solar powering the WP (modified 0 times) knarf Profile Ah, but that's the special part about this thing. Once installed, I won't have to bother with it anymore. It'll just sit there, snapping pictures and recording sounds. At the end of the trip, I'll have a complete 'sights & sounds' overview of the whole river, from Whitehorse to Emmonak (say, the Bering sea). No flimsy video camera's to take with me, no hassle, no nothing. Just paddle along, enjoy the scenery, scare the bears, etc. for about 2.5 months... 05-18-2001 10:28:47

RE:Solar powering the WP (modified 0 times) kray Profile | Email Is this who I think it is? Ben jij dat Frank? >> It will be hosting a webcam which will snap a picture every X seconds and record 'interesting' sound events >> (hence the two drives, the trip will take about 2.5 months so I need quite a lot of disk space). It runs a >> slightly modified Debian GNU/Linux 'testing' distribution (currently using the 2.4.4 kernel with some USB patches). >> Agressive use of APM keeps power consumption down (eg. screen blank after 2 minute, I won't need the screen anyway >> most of the time. The camera will be mounted on a headband, or just attached to the canoe somewhere, and merrily document >> the whole trip. Make sure the backlight goes off. Only blanking doesn't do much. Difference in power between a white or black screen is quite small. However the backlight takes 0.8A. Most powersavings on the webplayer shut off the disk and blank the screen, but don't take down the backlight power. There is also a possibility in underclocking the cpu. That will help in some power usage, but will be more responsible for less heat. Both topics are on my website. K-Ray -- The Journals 05-18-2001 12:02:54

RE:Solar powering the WP (modified 0 times) knarf Profile (-> kray) Ja, ik ben Frank... Hiya! (->rest) When you set the power save mode in BIOS to enabled, and configure the Linux kernel to use APM to blank the screen, the backlight will be turned off. That saves a lot of power... Also make sure the drives go to sleep when not needed (I have two drives in there, one of which is always sleeping... I shuffle files around to make sure only one drive is active...). There's more power to be saved by: - removing the modem (0.2A, according to kray's site) - disabling the bdflush daemon (this can be dangerous, as the buffers will not be flushed automatically... do a 'manual' sync() every now and then) - explicitly enabling all power save features for the MediaGX chipset (use the set6x86 program which can be found on the NSC website, and feed it the needed parameters. I can post some more on this if needed) - ... (more? sure...) 05-18-2001 12:58:30

RE:Solar powering the WP (modified 0 times) knarf Profile I put up some pictures of the machine on my site. Don't expect too much, they're just some webcam-grabs of the incomplete system... http://www.unternet.org/~frank/projects/webplayer/ruggedized/ If I have some time left, I will add more pix/explanation to the site. 05-18-2001 15:45:58

RE:Solar powering the WP (modified 0 times) kray Profile | Email >> - explicitly enabling all power save features for the MediaGX chipset (use the set6x86 program which can be found >> on the NSC website, and feed it the needed parameters. I can post some more on this if needed) >> - ... (more? sure...) I'm interested. 05-19-2001 09:12:03

RE:Solar powering the WP (modified 0 times) LD37 Profile knarf, that is pretty badass 05-19-2001 11:27:47

RE:Solar powering the WP (modified 0 times) Solidus Profile | Email You bastard =P Could I get ya to build me one of dem? lol =) 05-25-2001 14:00:22

RE:Solar powering the WP (modified 0 times) Clueless Profile | Email All I can say about this is FREAKIN' AMAZING!!! Excellent job!! Keeps us up to date on the website so we can follow your trip... 05-27-2001 09:50:47

RE:Solar powering the WP (modified 0 times) knarf Profile For those really interested in the subject of powering Webplayers with something besides the original powersupply, please note that the machine will NOT power up when fed a perfect 5V... My step-down converter first served a flawless 5V to the mainboard, but it would not budge. Turns out the original supply outputs anything between 5.3V and 5.6V, and settles around 5.35V with the system running. Yes, this means some parts are probably driven at a higher than normal (or useful) voltage and hence current. The machine seems to power up reliably at a voltage of 5.2V, so I adjusted my (second edition) step-down converter to provide 5.2V at the output. If you're using a MAX724-based step-down converter, you can simply use a 3K resistor in position R1 (R2 stays at 2.21K) to get this output (R1 is the 'hot' side of the divider network, R2 the 'cold' side. These (R1, R2) names are also used in the example circuit in the MAX724 datasheet. Also, make sure you use a big, hefty inductor, or the MAX724 won't be able to handle the current spike on startup. This goes especially for those Webplayers with hard drives added (like mine). An Amidon T106-26 core with 42 turns of 1.2 mm wire handles the job just fine in my system. I ripped mine out of a 200W AT power supply... And do not skimp on the input and output capacitors ! Use good, low-ESR, high-temp (105C) types (example: Roedersheim EMK). I use two of them in parallel on the input and output, since this halves the ESR which is GOOD (tm). The lower the ESR, the higher the efficiency of the converter and the longer the lifespan of the capacitor (since it does not get as warm as a high-ESR cap)! What ESR is you ask? They asked me in the parts store... It stands for 'Equivalent Series Resistance', and tells something about the capacitor's ability to handle higher frequencies (elco's are mostly resistive at higher frequencies). A high ESR in most switching power supply applications translates in a higher power dissipation in the capacitor, which in turn warms it up at the cost of both efficiency and the lifespan of the capacitor. If a capacitor is labeled as 'suitable for use in switching power supplies, it probably has a low ESR (and a high temperature range). High ESR often also translates in a higher ripple on the supply output and - in the case of a switching step-down converter - the input, since the capacitor is less able to block the high-frequency spikes which occur in such applications. These spikes can be harmful to sensitive equipment... like the Webplayer, I guess. An LC-filter on the output filters out the last remaining spikes and glitches, so my mainboard is spoon-fed with 'virgin' power... 05-27-2001 14:25:46

RE:Solar powering the WP (modified 0 times) simba Profile Knarf, Great information on your webplayer exploits both at your website and here. Looking forward to seeing the pix of your expedition. Could you post exact parts list or specs as well a circuit diagram and/or picture of the latest incarnation of the 12v->5.2v converter. For instance, I wonder, what is an LC-filter? This would help novice hardware hackers put one together and not fry our WP's. Thanks so much for your help and good luck on the trip. Jim 06-04-2001 12:19:03

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