A
Anonymous
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Who knows what forces are at work on this earth of which we have little comprehension. On this morning's TV there was an item dealing with an explanation for crop circles. Apart from hoaxes there is a small percentage for which there has been no logical explanation, but magnetic field surveys have now been carried out in fields where crop circles have appeared and some interesting things have emerged. In the vicinity of the crop circle there is a local magnetic anomaly, which exactly matches the shape of the circle. These local anomalies are said to shift occasionally and in so doing, generate electric currents in the ground which in turn cause the wheat to lie flat in the direction of the induced current. I don't know what qualifications or experience the scientist has who did the measurements but having done a fair bit of magnetic surveying myself, I am not convinced. The magnetic fields in question are very weak and even if they do move, the induced currents in the soil must also be correspondingly weak and I can't see a mechanism that will cause a crop to lay flat overnight with sharply defined edges. I would have thought that an obvious next test was to artificially pass a current through the ground in a field of wheat and see what happens.
Anyway, on to more serious things such as the rubber band powered metal detector. An extension of this idea is the clockwork metal detector which, like Trevor Bayliss' clockwork radio, has a wind up generator to provide operating power. Just think, no more batteries or worries about running out of power when miles away from anywhere. Just insert the key, crank it round a few times and full detecting power is restored. Other advantages are no batteries to leak or remove when the detector is in storage. No problems at airports, having to remove batteries. No batteries to dispose of; in other words, fully environmentally friendly. I mentioned the idea to one major detector manufacturer a few years ago with a negative interest reaction. I also spoke to Trevor Bayliss briefly on the subject and he thought there were possibilities, but only if it could be incorporated into the radio. The original idea behind the radio was to give people in poorer war torn countries, where batteries are hard to get, the opportunity to listen to the rest of the world and to get news from their own governments more easily. Many of these countries are littered with landmines, which cause injury and death to innocent people, women and children. If, in addition to the radio, there was an efficient built-in mine detector, then these unfortunate people could check there own land before walking on it or growing crops. The problem is that many of these anti-personnel mines have very little metal and it would be very difficult to design a cheap, sensitive enough detector to give efficient detection. It's no good detecting 50% of the mines, leaving the other 50% to maim and kill. Better to keep the land out of bounds for the time being. Many countries are putting a lot of money into research in de-mining and it is a very difficult problem to solve. One US company has a sensitive PI combined with ground penetrating radar and infra red sensors, all in one hand held unit with backpack electronics. Not something you can shoehorn into a portable radio let alone power from a wind up generator.
PI is out when considering a clockwork unit, unless you have a good energy recovery circuit on the lines of the Fisher Impulse, but IB, BFO or loaded oscillator circuits have possibilities. One UK inventor has a metal detector that is powered by the act of sweeping the search coil from side to side. The flexing motion of the shaft drives a small generator that powers the detector. Another advantage of both these ideas is that you don't have worry about forgetting to switch the detector off.
I still like the idea of a clockwork detector with a belt mounted power unit housing the spring motor, generator and necessary voltage regulators. The detector control unit could be shaft mounted as in normal practice and the two connected by a curly power lead.
What do you think? Would it be just a novelty or have real practical value?
Research fund donations gladly accepted <IMG SRC="/forums/images/smile.gif" BORDER=0 ALT="
">
Eric.
Anyway, on to more serious things such as the rubber band powered metal detector. An extension of this idea is the clockwork metal detector which, like Trevor Bayliss' clockwork radio, has a wind up generator to provide operating power. Just think, no more batteries or worries about running out of power when miles away from anywhere. Just insert the key, crank it round a few times and full detecting power is restored. Other advantages are no batteries to leak or remove when the detector is in storage. No problems at airports, having to remove batteries. No batteries to dispose of; in other words, fully environmentally friendly. I mentioned the idea to one major detector manufacturer a few years ago with a negative interest reaction. I also spoke to Trevor Bayliss briefly on the subject and he thought there were possibilities, but only if it could be incorporated into the radio. The original idea behind the radio was to give people in poorer war torn countries, where batteries are hard to get, the opportunity to listen to the rest of the world and to get news from their own governments more easily. Many of these countries are littered with landmines, which cause injury and death to innocent people, women and children. If, in addition to the radio, there was an efficient built-in mine detector, then these unfortunate people could check there own land before walking on it or growing crops. The problem is that many of these anti-personnel mines have very little metal and it would be very difficult to design a cheap, sensitive enough detector to give efficient detection. It's no good detecting 50% of the mines, leaving the other 50% to maim and kill. Better to keep the land out of bounds for the time being. Many countries are putting a lot of money into research in de-mining and it is a very difficult problem to solve. One US company has a sensitive PI combined with ground penetrating radar and infra red sensors, all in one hand held unit with backpack electronics. Not something you can shoehorn into a portable radio let alone power from a wind up generator.
PI is out when considering a clockwork unit, unless you have a good energy recovery circuit on the lines of the Fisher Impulse, but IB, BFO or loaded oscillator circuits have possibilities. One UK inventor has a metal detector that is powered by the act of sweeping the search coil from side to side. The flexing motion of the shaft drives a small generator that powers the detector. Another advantage of both these ideas is that you don't have worry about forgetting to switch the detector off.
I still like the idea of a clockwork detector with a belt mounted power unit housing the spring motor, generator and necessary voltage regulators. The detector control unit could be shaft mounted as in normal practice and the two connected by a curly power lead.
What do you think? Would it be just a novelty or have real practical value?
Research fund donations gladly accepted <IMG SRC="/forums/images/smile.gif" BORDER=0 ALT="
">Eric.