Design

Structured wiring: fiber optic or not?
A friend is having a new roof put on his his 50-year-old, flat-roof home. This provides access to all kinds of new wiring possibilities for the structure. He wants to do 2xCAT6 and 2xRG-6 throughout. I'm not sure what to recommend re. fiber optic. Is it too soon to know how this will be an advantage to ex... 5 Aug 2010 03:45

SCR and snubber LTSpice simulation
I have been working on a high current test set which uses SCR Solid State Relays to drive the primary of a transformer with 480 VAC mains power. There is a contactor which closes to apply power to the SSR, and then at a later time it is energized at the peak voltage point to reduce DC offset into the inductive ... 3 Aug 2010 16:57

What is this strange encoder motor?
Lots of new pictures here. http://igor.chudov.com/projects/Bridgeport-Series-II-Interact-2-CNC-Mill/24-Troyke-Rotary-Table-U12PNC/ This is a servo motor driven rotary table Troyke U12PNC. I thought that it was a simple servo motor with a tachometer and encoder on the back. Nothing could be further from the tr... 3 Aug 2010 19:09

Dumbed down consumer electronics: Adding DTV channels
I griped about the new USA Television system many months ago. The FCC has a web site where you can see all of the "dead spots" under the new system. The new system is apparently LINE OF SIGHT and is bothered by trees or dips in terrain. In Cedar Rapids where I live, (pop 100K) there is a big dead spot smack d... 3 Aug 2010 12:33

increasing employment by firing people
This is sort of like the faster-than-the-wind sail car: http://www.breitbart.com/article.php?id=CNG.b4a79e079069c2b3889441cfab5c4b25.61&show_article=1 John ... 3 Aug 2010 02:45

NimH AAA to 5V, suggestions?
I was looking for some 9V rechargeable blocks to power my sign_led display, http://panteltje.com/panteltje/pic/sign_pic/ to make it portable (put it in the car side window for example). Those are expensive, I had one but cannot find it. So I decided to build a small converter 1.2 to 5 V DC, singe AA cell about 2.... 13 Aug 2010 09:12

passive rc-bandpass with 0dB attenuation in the passband
Is it possible to make a passive rc-bandpass filter which has 0dB attenuation in the passband with only 4 components? nukey ... 8 Aug 2010 18:55

Peak value
Hi, I think my question got buried in the discussion so I am putting my question out there again. Please be patient. I am attaching two new drawings to show what I want. I do not know about accuracy but i would as say as much as accurate as possible. First link is as follows http://img828.imageshack.us/i/s... 8 Aug 2010 18:55

Data on 12V supply wires
Hello, I want to send half duplex digital data - moderate rate, say 1k bps or a bit faster - on a 12V, 2 wire, supply cable a few tens of metres long. It is to connect a remote sensor to the user's display unit, both portable. The parts need to be fairly small (eg a chip and a few resistors). I was hoping to b... 8 Aug 2010 18:55

Can I run a "brushless DC FAN" backwards?
I have a project that needs reversible fans. Can I make a brushless fan go backwards? Is it as simple as swapping the leads on the coils? Or is there more to it, like wrong phase for the magnetic pulse into the hall device? And then there's the question whether the blades will move as much air running backwards... 11 Aug 2010 11:27