T&L Publications

Thanks, the loading resistor seems to have done the trick

I am building the levitation project featured on: http://my.execpc.com/~rhoadley/magsus.htm (The schematics start about halfway down the page)<p>I have built the first circuit block on the page, which works with the one SS495A hall sensor that I have. However, when I try to use a SS19T hall sensor t...

I’m interested in learning more about the Op-Amp. I have a pretty good knowledge base of basic electronics, and want to expand this to learn some of the intricacies of designing with Op-Amps. None of my local bookstores carry any such books, and I’m hesitant to shell out 50 some dollars online towar...

How about fusion power? A lot of money has been invested in controlling fusion, but so far we can’t get more power out then we put in. Will this always be the power source of the future, or are we nearing a breakthrough? If so it would solve a lot of problems, just about no emissions or fallout, yet...

I have heard of a couple of different methods of sensing the position of the suspended magnet. One uses a Hall effect sensor. In one variation of this method a repelling force, rather then an attractive force is used to levitate. It does this by reversing the current to a coil based on the shifting ...

Sorry Stephen, I posted my last reply without refreshing the page and noticing your post. I found what you said to be very useful, I had not thought about the combined effects of distance and current, I always assumed the distance from magnet to electromagnet would be directly proportionate to the c...

Never mind… I have found out that the instability was caused from my current limited power supply, which was not giving the circuit enough current to operate correctly. After switching to a more powerful supply the project seems to work well. The two electromagnets seem to eliminate the before menti...

Thanks RonH for your help. I now have the project up and running. However, the suspended magnet is very unstable; much more so then the original design. That is, the magnet begins to oscillate until it falls or sticks to the top coil. In the original design, it would remain steady for at least a min...

I think "near enough" will suffice, the output never really needs to be at 0V, because that would equate to no current being supplied to the electromagnet. Also, I think the before mentioned application would require the two outputs to be approximately in step with each other, not exactly.

The project that this circuit will modify is for an electromagnetic levitator that I have built from a schematic I found in the Encyclopedia of Electronic Circuits, if you happen to have that book. If not, a very similar project is shown at: http://www.oz.net/~coilgun/levitation/home.htm I am hoping...

If I have a voltage output that varies linearly from 5VDC to 0VDC and I want a simultaneous output that varies inversely, from 0VDC to 5VDC, what circuitry can I add to the original output to achieve this? That is, how do I achieve output B, so that when output A is +5 output B is 0, and when output...

Check out the section on the "singing arc" at this link: <p>http://www.richieburnett.co.uk/cwsstc.html<p>be sure to download the video.

Thanks Jim, the electrolytic cap seems to have done the trick, although the output of the 555 is still affected slightly, causing the frequency and waveform to be a little erratic. This causes the circuit to draw about .25 amps rather then .15 or so. However once a load is connected the problem seem...

Brilliant! Your advice has worked perfectly. Instead of using a 7805 or 78L05, I took the easy way out and used batteries to power the 555 and my power supply to power the rest of the circuit. It works fine now. Anyways, I am trying to keep the part-count down, so if you have any suggestions on how ...

I have built a simple high voltage power supply based on a 555 timer. The 555 is wired the same as in the first figure at http://www.doctronics.co.uk/555.htm and is configured so that it operates at about 16kHz with a 50% duty cycle. The 555 drives a TIP41C power transistor through a 120-ohm resisto...