02-01-2014, 12:19 PM | #51 |
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But wouldn't this mean that anyone going down a big hill on a segway would be adding to Global Warming?
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Karl Ian Sagal To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. "Well done is better than well said." (Ben Franklin) Bene factum melior bene dictum Proud past President of SEG America and member of the First Premier Segway Enthusiasts Group and subsequent ones as well. |
02-01-2014, 06:18 PM | #52 | |
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Sorta what I said earlier....................
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02-10-2014, 07:21 AM | #53 | |
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The only solution is to make it a very inefficient lightbub (in the visible spectrum). In other words, a space heater. And since nobody deliberately designs inefficient light bulbs, you may as well go with a power resistor and a separate LED lighting system. The result will be more reliable, and cheaper than some design based on specialized bulbs. Add to this the fact that the power to be dissipated depends on the slope and instantaneous demands, and I just don't see lightbulbs as being a suitable solution to dumping the energy. It could be done, but the illumination aspect is not working to your advantage. Also, I'm taking your 250 W at face value. I presume your calculations were reasonable based on the physics of the mass of rider + segway descending at some particular rate. That's a reasonable approach for estimating average power, but we have to consider that the motors are capable of much higher peaks -- almost 2 KW apiece. (per Doug Field, in a post here: http://forums.segwaychat.org/archive...hp/t-9400.html) As I stated, an incandescent bulb is a space heater operating near the failure point. They're not very tolerant of being overdriven for even short periods of time. They have very low thermal mass, so they heat up very quickly. As an exercise in physics, it makes perfect sense. As a practical design -- not so much. A lot of engineering consists of considering "what could possibly go wrong with this perfectly logical plan?"
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Bob Kerns: To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. , To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. Obviously, we can't have infinite voltage, or the universe would tear itself to shreds, and we wouldn't be discussing Segways. |
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02-10-2014, 12:01 PM | #54 |
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Thanks, Bob.
I am quite aware that a light bulb would not be a good solution (for all of the reasons you mentioned, plus a few more). I stated it that way so that most folks would have some way to compare it with a familiar object. Saying "power resistor" or "small space heater" or "coffee pot" or "crock pot" would have worked, of course - I'm just not sure it would have been quite so illuminating. Are you still intending to write up the physics, to help Karl? |
02-11-2014, 10:08 AM | #55 | |
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It also illustrates nicely the difference between physics and engineering. All engineering is built atop of physics, but engineers search for solutions among a myriad of physical constraints. I am still intending to write something up, but the earliest it could happen is this weekend. Being sick for a month has left me a bit behind.
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Bob Kerns: To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. , To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. Obviously, we can't have infinite voltage, or the universe would tear itself to shreds, and we wouldn't be discussing Segways. |
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04-13-2014, 12:19 PM | #56 |
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I believe this writeup would be helpful, if you find the time to do it.
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04-13-2014, 10:51 PM | #57 |
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I haven't forgotten about it, but got a software release to get out shortly, so it's not going to me Real Soon yet...
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Bob Kerns: To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. , To view links or images in signatures your post count must be 5 or greater. You currently have 0 posts. Obviously, we can't have infinite voltage, or the universe would tear itself to shreds, and we wouldn't be discussing Segways. |
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