T&L Publications

What you need is a normally closed opto relay such as Omron G3VM353A; it is open when energized. Mouser #653-G3VM-353A.

What you want to do is exactly like a printer. You can use a DC motor with a segmented disc (counting wheel) and sensor to know how far the thing has moved, or you can use a stepping motor and count the number of steps. You will need to be able to program a microcontroller which will handle the coun...

My apoligies for taking so long to get to this thread. I understand the confusion, I don't understant it myself! I don't know what I was thinking, I have only one half of the needed circuit. This circuit can only drive the positive alternation of the audio, as was correctly noted. I think one soluti...

I imagine that some low quality solar cells have significant reverse leakage. The ones I have tested have no measurable reverse leakage and I do not use a diode.

Look inside, the vertical adjustment may be labeled. Otherwise you need to buy a service manual.

"the pads in Eagle are often so small that even if I don't ruin the pad between etching and drilling, there's not much room for the solder to stick. " The pads are sized for plated thru holes. For hand soldering, it would pay to go into the library and change the sizes. It is easy to do, just click ...

So, what is the purpose of the capacitors?

I know that a single phase motor can be reversed if it is built that way. Reversable motors have two stator windings and you reverse one to make it turn the other way, I believe.

From the picture it appears that there are 8 LEDs arranged around the circle, which are lighted one after another. All you need is a "LED chaser" circuit and some packageing. But, for $22.95, I don't think you can build one that cheap.

If you ask Allen-Bradley, they might give you one for free. I can't hurt to ask. Manufacturers often give out free samples.

When I worked in Ocean Systems, we had to make underwater connections that would survive 2000 feet of sea water. We used a sticky material similar to what is now called "bitchethane". The higher the pressure, the better it sealed.

I believe that the most correct answer to "why have a center tap" is that full wave rectification with 2 diodes has AC flowing in the secondary so less iron can be used and still avoid saturation. Full wave bridge rectification works that way also but back in the day of selenium rectifiers, a center...

I don't have mine yet, but I have noticed that publication date varies quite a bit, month to month.

High speed modems are able to send 56K over 3kHz phone lines, take a look at how they do it. Phase modulation, but I don't know the details.

The 2 pin winding is probably an 8 ohm secondary. connect an audio oscillator to the secondary and measure the transformation ratio. The power rating can be estimated from the size and weight. What else do you need to know?