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Will ,there is no squeeze on the reed switch of my scooter, and using a Hal effect semiconductor with diodes and other electronics to achieve the same thing is not in the cards with me. I am not going to pass a magnetic field over a semiconductor that must depend on other electronics and a power source, when I can do it with a reed - an auto is a different situation, and when I go "Downtown", which I have done more than the sum total of everyone on both of these lists, I do it the way that gets me back. You will come to appreciate this in this particular application, and if you are dumb enough to ever start cave diving, you will swear by it. Also keep in mind that the reed has its own protective cover and is out where it can be easily changed if damaged. The relay is changeable in seconds as well. The key to both of these items is that they are commonly available everywhere in the world , at cheap prices off of the shelf, and are the only two pieces of "electronics" in the scooter. Do not forget that we have plenty of engineers on our team, and as you know Bill Mee taught this stuff at Brown University, is a biomedical , elecetronic, computer, mechanical and electrical engineer, and designs and programs medical electronic instruments for a living. He is Preisdent ( or whatever ) of Verimed. He made a talking decompression wrist dive computer fifteen years ago, and did deep wreck dives with it here in Ft Lauderdale before one could even buy a wrist computer other than the bendomatic. We are not ignorant, stupid, or crazy ( despite the fact that we are cave divers) - we know what we are doing, and have thought it all out. By the way, 4 of the guys on the team were involved in the EX19 rebreather, and guess what they think about the scooter? By the way, we went through that same exercise you are doing with Bulhmann ten years ago, and you are right that the old version is the only english.. he is dead now, but what I did after I discovered his stuff deos not work is to speak to the other guys who were there with him and find out what does work, and that is how I cam up with the modification that I use now ( that and experimantation over the last ten years). William M. Smithers wrote: > > On Thu, 8 Jan 1998, CHK BOONE wrote: > > > << The real point is that when it comes to these scooters (and life support > > systems) a reed switch, despite the simplicity and seeming cheapness of > > this electronic artifice, is a better choice than relays, op amps, power > > mosfets and other miscellaneous electro goobery. > > While I absolutely agree with George that simplicity is best, > it does pay sometimes to evaluate reliability vs. simplicity. > > George, I don't mean to beat a dead horse here, but the simple truth > is that sometimes solid state electronics are simply better. > This doesn't mean you have to have three relays hooked up > in series or some other "goobery". Point in fact, let's > take a look at Detroit, where the engineering boys know > a shitload about reliable electronics. > > Do you see a reed switch in ABS braking systems? Ahh, no, > I don't think so. Where the rubber meets the road, and > you need five million repeatable events, reed > switches, in all their mechanical simplicity, just don't > cut it. The boys in Detroit use Hall-effect sensors, which > don't have crushable glass tubing or slapping pieces > of metal. At depth, where things squeeze, this is extra important. > > While I agree that MOSFETS are stupidity for scooters, > and that relays are the best power-switching solution > for the job, the simple fact is that Hall-Effect sensors > are a superior solution to mechanical reed switches. > > Techno-geekery for it's own sake is pretty rediculous, but > there are plenty of areas where engineers know their > shit cold, and reed switches vs. Hall Effect sensors > are one clear example. > > (that said, I did just order one of George's scooters, > after my shitty scooter shit the bed at a lousy 160fsw) > > -Will > -- > Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. > Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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