ante

A leaf blower is not needed; something smaller will be more than enough! It depends on the size of the fire you need which in turn depends on the amount of metal you like to melt at one time! Here is room for experimenting!

I tried Google ´SLC 500´ and got 1 970 000 hits……… it’s a good place to start I guess! ;D

I can’t say I have any experience in that field, no! Sorry can’t help you there! ;)

Hi Chris, I believe the cheapest way might be using a coal fire with a blower like a blacksmith.

Yes, I know what you mean. If you Google ´reed relay´ you get an idea of how such a relay looks, there are many shapes and sizes. Sometimes you can pull out the glass element from this type of relay and use it for other purposes. If you find mercury relays or mercury wetted relays, just leave them and do not tamper with them! ;)

Hi, Yes you can keep the transformer cooler if you bolt it to a metal chassis and put some heatsink compound in between. If it’s a toroide transformer you do it the opposite way, space it from the chassis and install a fan to keep it cool. Before you do any of the above, make sure you are not overloading your transformers ratings.

Well, reed switches can be hard to find also for dumpster divers! Try older copiers and faxes even in some old printer or buy one, they are not very expensive. ;)

Yes, I have tested many steppers this way to determine the suitability to generate power. Not every stepper becomes a good alternator but every one I have tried so far has a noticeable inertia when shorted.

Hi Chris, Ok, the easy way: reed switch and magnet! This is very close to your original idea! Attach a magnet to a cylindrical float (plastic); put the float inside a tube (also plastic) which has an inner diameter just to fit the float. Close the bottom end of the pipe and leave the top end open and above the surface at all times. Attach a reed switch on the outside of the tube; make a small bracket which might be kept in place with a stainless steel house clamp for easy adjustment. Drill some small holes along the pipe (size and distance of the holes depends on the size of everything else) this will have a dampening effect on the float when you dive into the water or playing with your rubber duck. ;D

Hi Chris, It’s from the cover of a book but I can’t remember which book unfortunately! Maybe someone else knows which book it is? It looks like it could be out of your homepage though! ;) B T W you must be a millionaire selling penny's for dollars! ;D ;D

Is this related to electronics?

There is no big problem using electrodes to control a relay. Just like an automatic bailout pump for a daycruiser a timer closes the relay 5 minutes or so after continuous contact between the electrodes, this will cure the problem. No rattling relays! But if using AC the electrodes can be partly submerged at any given time and the capacitance between them indicates the level. If you like to avoid electronics, try the simple way with a reed switch. To get the pump start-to-stop range as wide as possible try to find a strong magnet, cannibalize one from an old hard drive they are very strong.

My experience with sensors is: use stainless steel rods and AC voltage for sensing. Just my two cents. ;)

I believe whatever subject in robotics you are looking for its in some of these books. Are there any particular things you know exists in the books you are looking for and nowhere else?

Hi AG, When extracting RAR files: I always use the right mouse button to pickup and drop the compressed file on an empty folder and choose extract here! This is less fuzz and no nagging! ;D

Hi AG, Yes, just twist it between you fingers will do the job!

Hi smuralisankar, There are many robotics books here: http://ebook.blogfa.com/cat-1.aspx I am not sure about the once you asked for but I believe you will find most of what you need in here! Are you familiar with the SERVO magazine? It’s all about robotic stuff!

And, sort of an update or overall mod here in EPE 03-2003: These are truly battery less torches! 03-2003.pdf

Hi AG, After some research I found this article in EPE 10-2000: at page 724 - [attachment deleted by admin]

Then you have a faulty stepper motor or some other kind of motor! Stepper motors will even whiteout shorting the wires have clearly noticeable steps, and when shorting the leads it will be very sluggish! Unless of curse the magnets or the windings are gone, then it will spin easy!

Hi AG, There are many ways you can turn the stepper. If it has a belt wheel it’s enough to turn it between your thumb and index finger. A small crank will work fine too, windmill, gears or rack and pinion with a spring! There are endless possibilities! Even a small stepper generates a fair amount of power, if you got one in your junkbox try turning it with your fingers and then short all the wires together and try to turn it! ;D

Hi MP, Rabid says: “looking at the plans for the “"Simple but reliable car battery tester"”! I just wanted to make sure he didn’t think this circuit works like one!

There are some values issued by the authority who tells us when it’s dangerous but the accumulated influence is not possible to know. No one can answer this for another 10 to 15 years when we have had time to study the effects and diagnosed the users! :o Take Care! ;)

Unless it’s illegal there is no reason to “extract” the code from a chip! ;)

Hi, If you need a battery less torch it’s much better to use an old stepper motor and a few diodes or rectifiers and some bright LEDs. It’s possible to charge some Ni-Cads with the stepper or if you need some backup and don’t want rechargeable cells you can use a Gold-cap or two! Almost any old stepper will work fine for this!