#181
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More About Lights
On 2017-03-16 15:07, Jeff Liebermann wrote:
On Thu, 16 Mar 2017 10:20:43 -0700, Joerg wrote: There is no need for 27.5W but there is for 8-10W. That should be reasonably possible, else the dynamo would have smoked out during their testing. If all you're powering are head and tail lights, 10 watts should be sufficient. However, if you're powering other devices (GPS, smartphone, rear view camera, electric shifter, fog horn, etc), then more power is better. I also have to power an MP3 player. No smart phone since I won't likely buy one until they can function as good as a GPS devise even while off-grid. Still, 10W suffices because I can ratchet down or turn off the light on many trails and MUP. It's mostly needed on roads which I try to avoid where I can. http://www.ebay.com/itm/122373782338 (Yet another project that I'll never finish). That is a neat little instrument. Yep. I don't have one yet, but it's a real temptation to install one on all my various unmetered power supplies and battery packs. However, there's a catch. The common ground is positive (+), not negative. You can see that in the schematic: https://img.alicdn.com/imgextra/i3/121163002/TB2NoBogpXXXXahXpXXXXXXXXXX_!!121163002.jpg where the + leads of both the "DC in" and the load are connected together. The only ways I could make it work in a negative ground system was either an isolated power source, isolated load, separate isolated power supply to run the meter, or a DC-DC inverter. That would be a show stopper in most applications. Got to have high-side current sensing. Impediment, not show stopper. What most users have done after turning the + wire into an impromptu fuse, is to install a small isolated DC to DC inverter. The problem is that the current measuring part of the circuit needs to have some source of power to run the devices used. If one part of that power source happens to be grounded to either the + or - input of the voltage measuring part, it won't work. So, the vendor recommends either floating the input or output grounds, using independent volt and amp meters, or using an isolated power supply to power the conglomerated meter. I know that one can get such DC to DC inverters quite cheaply, but I haven't bothered to search for them. I'll post something if I find one as I think it might be useful for your battery pack and dynamo. Digikey has lots of those. But when such extra measures are needed this all gets old. Why can't they do high-side sensing? It ain't rocket science. From a dynamo it's still feasible after things have been turned to DC because the hub versions usually have two ground-free terminals. Bottle dynamos unfortunately not. However, when doing MPPT there already is a micro controller which can then also perform the job of energy metering. Yep. I've setup some cheap MPPT solar charge controllers (from eBay). The better one's have extensive monitoring capabilities, usually on an LCD or OLED display. If you're counting and budgeting coulombs, it's a good way to do it. I would not need that though, maybe just an indicator of whether the dynamo is able to feed enough for a given light setting. Easy enough. The power output of the dynamo is directly proportional to the RPM and unaffected by the load. No really. Keep in mind the various losses. ... The load might change radically, but the dynamo will only deliver XX watts at XX RPM. You could just measure the RPM, build a lookup table in some kind of NVRAM, and display the output power. All I need is a sensitive voltmeter. That tells me whether my battery juice is being consumed or juice is being added. I have seen waterproof LED meters with two digits after the decimal point for less than $5. This is what I am going to add some day. It will also let me see the charge state before heading out on either bike. Or, you could get fancy, measure the load voltage and current, and calculate the power needed to run the lights or whatever. Then compare the input power available, with the average output power needed. If there's not enough input power available, you need to shed some load, or pedal harder. Nah, too fancy :-) Even that is expendable if you have a voltmeter riding along with the Li-Ion battery. In my case I'd just have to make sure it won't get close to 7V where the electronics will eventually shut things off. If you do go over, you might want to shed the load slowly or you might lurch forward as pedaling suddenly becomes easier. With a 10-15W load? Nothing beats trying it on the bench, using a variable speed drill or similar. I haven't observed a sharp knee effect on any of them so far. Which probably explains the large number of bulbs I blew out in the 80's when I had to get somewhere fast. Yeah, I should do that. However, as I previously mumbled, I'm overloaded, busy, lazy, and uninspired right now. Same here. The MTB still needs to be fixed, taxes to be done, then there is work, and right now I am busy with a much higher priority. I brewed a Belgian Tripel this morning and this afternoon a Superior Strong Ale is in the process. -- Regards, Joerg http://www.analogconsultants.com/ |
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#182
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More About Lights
On 3/17/2017 12:58 PM, Joerg wrote:
On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. |
#183
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More About Lights
On 3/17/2017 1:09 PM, Joerg wrote:
On 2017-03-16 15:07, Jeff Liebermann wrote: On Thu, 16 Mar 2017 10:20:43 -0700, Joerg wrote: There is no need for 27.5W but there is for 8-10W. That should be reasonably possible, else the dynamo would have smoked out during their testing. If all you're powering are head and tail lights, 10 watts should be sufficient. However, if you're powering other devices (GPS, smartphone, rear view camera, electric shifter, fog horn, etc), then more power is better. I also have to power an MP3 player. No smart phone since I won't likely buy one until they can function as good as a GPS devise even while off-grid. We're already there. Lots of off-grid GPS/mapping apps. No need to use data or have a data connection. Topos available too. Not free. Is it as good as a dedicated GPS? Not really because the internal GPS antenna on a phone is inferior, but for outdoors a phone is good enough. You really need to get with the program and buy yourself an iPhone 7+, and iPad Pro with LTE data, a Macbook, a Mac Pro, an Apple watch, and an Apple TV. Wait a few months and drive down to Cupertino and buy everything at the new Apple store. |
#184
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More About Lights
On 2017-03-17 13:53, sms wrote:
On 3/17/2017 12:58 PM, Joerg wrote: On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. And then you have to cool that zener. And hand-pick one because of tolerance. Also, those things are soft. Better to build an "active zener" with a TL431 and a transistor. However, I'd prefer a switch mode regulator that can handle north of 50V because then you can capture all the juice generated on that long downhill section. I have a few of those when riding into towns west of here. On the way back, of course, it's sweating and suppressed cussing because those 1000+ feet have to be gained back. -- Regards, Joerg http://www.analogconsultants.com/ |
#185
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More About Lights
On 2017-03-17 13:59, sms wrote:
On 3/17/2017 1:09 PM, Joerg wrote: On 2017-03-16 15:07, Jeff Liebermann wrote: On Thu, 16 Mar 2017 10:20:43 -0700, Joerg wrote: There is no need for 27.5W but there is for 8-10W. That should be reasonably possible, else the dynamo would have smoked out during their testing. If all you're powering are head and tail lights, 10 watts should be sufficient. However, if you're powering other devices (GPS, smartphone, rear view camera, electric shifter, fog horn, etc), then more power is better. I also have to power an MP3 player. No smart phone since I won't likely buy one until they can function as good as a GPS devise even while off-grid. We're already there. Lots of off-grid GPS/mapping apps. No need to use data or have a data connection. Topos available too. Not free. If it's reasonably priced it is ok. However, every time I asked dirt bikers who venture out into the sticks in Nevada they said that they tried their smart phones but that it really doesn't work well without a Garmin or other native GPS device. Is it as good as a dedicated GPS? Not really because the internal GPS antenna on a phone is inferior, but for outdoors a phone is good enough. It is quite mountainous out here and that might be the problem. You really need to get with the program and buy yourself an iPhone 7+, and iPad Pro with LTE data, a Macbook, a Mac Pro, an Apple watch, and an Apple TV. Wait a few months and drive down to Cupertino and buy everything at the new Apple store. Only over my dead body :-) -- Regards, Joerg http://www.analogconsultants.com/ |
#186
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More About Lights
On 3/17/2017 8:00 PM, Joerg wrote:
On 2017-03-17 13:53, sms wrote: On 3/17/2017 12:58 PM, Joerg wrote: On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. And then you have to cool that zener. And hand-pick one because of tolerance. Also, those things are soft. Better to build an "active zener" with a TL431 and a transistor. However, I'd prefer a switch mode regulator that can handle north of 50V because then you can capture all the juice generated on that long downhill section. I have a few of those when riding into towns west of here. On the way back, of course, it's sweating and suppressed cussing because those 1000+ feet have to be gained back. If you're trying to charge USB devices, you should at least look at this design: http://fahrradzukunft.de/12/minimal-lader/ It seems to be much simpler than what you're considering. -- - Frank Krygowski |
#187
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More About Lights
On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote:
On 3/17/2017 8:00 PM, Joerg wrote: On 2017-03-17 13:53, sms wrote: On 3/17/2017 12:58 PM, Joerg wrote: On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. And then you have to cool that zener. And hand-pick one because of tolerance. Also, those things are soft. Better to build an "active zener" with a TL431 and a transistor. However, I'd prefer a switch mode regulator that can handle north of 50V because then you can capture all the juice generated on that long downhill section. I have a few of those when riding into towns west of here. On the way back, of course, it's sweating and suppressed cussing because those 1000+ feet have to be gained back. If you're trying to charge USB devices, you should at least look at this design: http://fahrradzukunft.de/12/minimal-lader/ It seems to be much simpler than what you're considering. I use this device: http://images.wisegeek.com/standard-us-power-outlet.jpg -- Jay Beattie. |
#188
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More About Lights
On 3/17/2017 10:55 PM, jbeattie wrote:
On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote: On 3/17/2017 8:00 PM, Joerg wrote: On 2017-03-17 13:53, sms wrote: On 3/17/2017 12:58 PM, Joerg wrote: On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. And then you have to cool that zener. And hand-pick one because of tolerance. Also, those things are soft. Better to build an "active zener" with a TL431 and a transistor. However, I'd prefer a switch mode regulator that can handle north of 50V because then you can capture all the juice generated on that long downhill section. I have a few of those when riding into towns west of here. On the way back, of course, it's sweating and suppressed cussing because those 1000+ feet have to be gained back. If you're trying to charge USB devices, you should at least look at this design: http://fahrradzukunft.de/12/minimal-lader/ It seems to be much simpler than what you're considering. I use this device: http://images.wisegeek.com/standard-us-power-outlet.jpg It's not very portable. -- - Frank Krygowski |
#189
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More About Lights
On 2017-03-17 20:50, Frank Krygowski wrote:
On 3/17/2017 10:55 PM, jbeattie wrote: On Friday, March 17, 2017 at 7:00:01 PM UTC-7, Frank Krygowski wrote: On 3/17/2017 8:00 PM, Joerg wrote: On 2017-03-17 13:53, sms wrote: On 3/17/2017 12:58 PM, Joerg wrote: On 2017-03-17 12:11, sms wrote: On 3/13/2017 12:28 PM, Joerg wrote: snip You could stick in a Murata LXDC55FAAA-203 http://power.murata.com/data/power/LXDC55FAAA-203_data_sheet_E.pdf instead of the zener and do a USB version also with only three parts. But I know that you love designing your own switchers. $3.50? Mon Dieu! :-) I got some of the Murata LXDC55FAAA-203 units from Digikey for use at work. I guess I didn't realize from the picture on the data sheet just how tiny these things are. Maybe I'll buy some more and try building some dynamo to USB adapters. Be carful with that 16V abs max input limit. When the load current drops this can easily be exceeded by a dynamo, big time. You could burn off the excess with a zener diode or TVS (though _not_ MOV) but these have large tolerances and could burn out if not well heat sinked. I think you need somthing automotive here, some circuit that can stomach 50V or more. I'd just stick a 15V 5W zener in there for the rare times that the dynamo is exceeding 11VAC. If I were going to sell these I'd do something more robust. And then you have to cool that zener. And hand-pick one because of tolerance. Also, those things are soft. Better to build an "active zener" with a TL431 and a transistor. However, I'd prefer a switch mode regulator that can handle north of 50V because then you can capture all the juice generated on that long downhill section. I have a few of those when riding into towns west of here. On the way back, of course, it's sweating and suppressed cussing because those 1000+ feet have to be gained back. If you're trying to charge USB devices, you should at least look at this design: http://fahrradzukunft.de/12/minimal-lader/ It seems to be much simpler than what you're considering. A zener diode is not a suitable device to limit USB voltage. The upper limit in the standard is 5.25V. https://en.wikipedia.org/wiki/USB He should have at least a TL431 with a transistor as a shunt in there. Anyhow, that is not why I'd invest in a hub dynamo some day. I want it to be able to supply my 8.2V power bus on the road bike and charge its Li-Ion battery pack. The MTB has the same but that will unlikely ever get a hub dynamo. The smart thing is to at least have poor man's MPPT and for USB provide a decent secondary regulator, preferably switch-mode as well. I use this device: http://images.wisegeek.com/standard-us-power-outlet.jpg It's not very portable. I had some on my road bike a couple of weeks ago. Along with other electrical gear I bought for a rework session. -- Regards, Joerg http://www.analogconsultants.com/ |
#190
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More About Lights
On Fri, 17 Mar 2017 17:03:19 -0700, Joerg
wrote: However, every time I asked dirt bikers who venture out into the sticks in Nevada they said that they tried their smart phones but that it really doesn't work well without a Garmin or other native GPS device. I've had the same experience when I try to run the GPS in "airplane mode". The GPS uses location data from the cell sites (AGPS) to improve its E911 accuracy and shorten acquisition time. Turn off the cellular part of the phone, or try to use GPS in an area where there are no cell sites is a problem. "Using an Android GPS in Airplane Mode" http://backcountrynavigator.com/using-android-gps-airplane-mode/ There are also issues with the antenna. Size matters and the bigger patch antennas used in handheld GPS receivers offers much better sensitivity and view of the sky. I have a collection of about 10 assorted GPS receivers. Occasionally, I do a comparison of performance in challenging areas (hills, mountains, trees, indoors, underground garages, highly reflective environments, RF polluted environments, etc). If I have a nearby cell site to use as a starting or reference point, my Moto G smartphone does quite well. My Samsung S6, not so well but good enough. However, if I go into "airplane mode" to save battery power, performance sucks. The main problem is that without the position sanity check provided by AGPS, the smartphone GPS will produce wildly erratic positions caused by reflections, often miles away from my actual location. Some of the handheld mapping GPS receivers do the same thing, but not as badly. There is also some mapping trickery involved when using maps and AGPS. In order to improve (or fake) accuracy for E911, mapping smartphone apps like to round off positions to coincide with a roadway. It's a fair assumption that someone using a GPS map program would be on some kind of road. That's great, until you ride off the road and your GPS tracker thinks you're still on the roadway. So far, it hasn't been a problem. You really need to get with the program and buy yourself an iPhone 7+, Only over my dead body :-) I'll resist the temptation to say something clever about your destructive testing methods. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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