4 more posts in this thread. [Missing image file: la foto 1.jpg]
So dynos, i have been reading about synchronous motors, and i actually got one from a microwave , i was playing around with it and suddenly when i was spinning the propeller i got shocked, by touching the terminals
i pulled out a multimetter to meassure voltage in CD and CA and both are getting generated, (way more CA than CD)
so now i wonder
Why is this happening?
Is it generating AC or DC ?
Whats the max voltage i can get from spining this thing ?
I have to go out i will plug it to an oscilloscope later tonight however i wanted to ask so maybe someone gere can give me any leads of why is this happening
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I want to put up some shelves on a wall in my kitchen. Attached picture shows the situation. It is a drywall wall, with standard size drywall slabs, 60cm wide, supported by wooden beams behind the drywall.
Now I know that I can easily put up shelves using supports screwed into the support beams, in the picture I called the beams 'a', 'b', and 'c', but that would mean having to go with either 60cm or 120cm shelves, by placing supports at 'a', 'b' and 'c' for example for a 120cm shelve.
But what if want the shelves to run for, say, 90cm or 100cm, starting at the left edge of the wall? How should I safely mount a shelve meant for holding cookbooks (which are often large and heavy) in this situation?
If such a 100cm shelve starts at the left side of the wall, I figure I should fix a support at least at 'a', possibly at 'b', and use drywall anchors for the shelve end between 'b' and 'c', but the support at 'b' would look out of place because it isn't centred. What are my alternatives? Am I underestimating the shelve bearing properties of drywall and drywall anchors?
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I have a Morse code key and I want to automate the movement of it. I'm trying to think of the best way to do so, and I'm coming up with the idea of using a small electromagnetic solenoid like picture related.
The first idea was to use a big electromagnet hidden underneath the key and attach a small ferrous piece to the key itself and pulse the electromagnet in order to attract the key and rely on the spring within the mechanism when the current is cut to pull it back again. I was going to use the transformer out of an old microwave or something but this seems like overkill. The voltages required would be mains.
Something like a small solenoid could be used to push it but I'm not sure if the solenoid will 'pop' back out when current is cut and with what kind of force. The technical sheet describes it as a 'pull' type so I'm assuming that when current is applied, it pulls itself in and when cut, it pops out again, or maybe not, maybe it relies on gravity or a flip in polarity? I'm not sure.
Also the control mechanism. I was thinking of getting a little IC capable of acting as a pulse width modulator and then controlling it with that. Not sure if I can find some that are happy outputting 6V on rails, I'm only used to using tiny little audio electronics.
Any advice or ideas? It'd be much appreciated, I hope I've explained what I intend to do fully. The intention is to have a box with a Morse code key on the top which moves and triggers itself with mostly a hidden mechanism.
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I'm currently working on an interactive art project and I've run into a bit of a snag. Long story short, I need to trick Windows 7 into thinking that two USB touchscreen overlays are actually one large touchscreen (basically the same way it treats two monitors in extended display mode.) The problem is that Windows does not naturally support dual touchscreens; it either completely ignores the input from one of them, or recognizes them as the same, mirrored pointing device (the same way it treats two monitors in clone mode.) What I need is either a piece of hardware (arduino?) or software or combination thereof that would fix this problem, preferably cheaply. All I can find on Google is that there might be some proprietary drivers out there, but other than that there is little to no documentation on the subject. If one of you could at least point me in the right direction as far as hardware vs. software that would be great…