Breaking News
View Comments: Oldest First | Newest First | Threaded View
Page 1 / 2   >   >>
cjperkins
User Rank
Rookie
Why so complex?
cjperkins   9/26/2013 3:32:53 PM
NO RATINGS
Wouldn't a simple RC filter have cleaned up the 60 Hz to get a stable clock?

DU00000001
User Rank
CEO
Re: Why so complex?
DU00000001   9/27/2013 9:42:33 AM
NO RATINGS
It's not so easy to create a monster :)

Though the schematics are difficult to read I can identify some R's on the primary side. Thus an adequate C should have done the trick.

Caleb Kraft
User Rank
Blogger
Re: Why so complex?
Caleb Kraft   9/27/2013 11:55:11 AM
NO RATINGS
that is the funny thing about so many stories involving solving a problem. Someone always comes along with a single sentence that would have probably saved you hours... a long time after the fact.

WKetel
User Rank
Rookie
A tuned filter?
WKetel   9/28/2013 9:10:24 PM
NO RATINGS
My first thought would be a tuned LC filter, resonant around 120 Hz. That would have avoided the noise problem and been far more reliable, and a whole lot cheaper.

When I was designing test equipment for factory floor operation we almost always put a Sola Brabd constant voltage transformer ahead of the controls and instrumantation power input. It was always cheaper than even one service call to fix a machine, and it gave us a reputaion for producing very reliable testing machines. The noise on the waveform on the scope traces looks a bit like it comes froman inverter drive circuit for a medium horsepower motor.

Andy_I
User Rank
Rookie
clarity
Andy_I   10/4/2013 1:18:13 AM
NO RATINGS
Do the people who write these articles ever bother to see what they look like when they get published?

I mean, COME ON, EE Times!  WAKE UP!  This is such a joke.

 

 

David Ashton
User Rank
Blogger
Re: clarity
David Ashton   10/4/2013 1:23:14 AM
NO RATINGS
@andy....we're looking forward to seeing yours soon then, to show us how it should be done....

gigavolt
User Rank
Rookie
Re: clarity
gigavolt   11/12/2013 9:40:19 PM
NO RATINGS
I think Andy might be talking about the formatting of the article done by EEtimes, and not the author, which is me. The text has clearly been revised, and very well I think. The problem lies in the resolution of the images. You can not make out the text in the scope images at all, and the schematic is unreadable as well. It's also difficult to take in how bad the signals really were with these low resolution images. They really make the article somewhat nonsensical due to lack of information.

The URL below is the article as I originally wrote it, and much more readable.

http://www.24hourbudget.com/contest/

gigavolt
User Rank
Rookie
Re: Why so complex?
gigavolt   11/12/2013 9:47:22 PM
NO RATINGS
On the A/C side? No. They tired that long before I was called in.

gigavolt
User Rank
Rookie
Re: Why so complex?
gigavolt   11/12/2013 9:53:11 PM
NO RATINGS
These comments were the first thing I thought of as well. There was a lot of stuff I couldn't get into because of the word limit. But long story short, I tried various filtering techniques, but none would work. The schematic here is really unreadable, but I posted a link to the original article in a comment above. There, you can see the schematic and other images with better resolution. You will see that there are two opto-couplers converting the line frequency to a digital signal. One is the "phase", which outputs a 60 Hz 50% duty signal. The other is "ISR" which outputs a 120Hz 10% duty. I was able to clean the 50% with a .01 to ground. But when I tried that on the 10%, the computer wouldn't start. Everything I did to the ISR signal caused a boot failure. I'm not really sure why. Replacing the signal was the only alternative left.

gigavolt
User Rank
Rookie
Re: A tuned filter?
gigavolt   11/12/2013 9:56:48 PM
NO RATINGS
THe machine;s been running for over a year now, WKetel. And no failures yet. I would think it's pretty reliable. I agree a filter would be best, but I could find none that would work. And when you're faced with "make it work or I want my money back", you do what you got to do to make the customer happy.

Page 1 / 2   >   >>
Flash Poll
Radio
LATEST ARCHIVED BROADCAST
Join our online Radio Show on Friday 11th July starting at 2:00pm Eastern, when EETimes editor of all things fun and interesting, Max Maxfield, and embedded systems expert, Jack Ganssle, will debate as to just what is, and is not, and embedded system.
Like Us on Facebook

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Times on Twitter
EE Times Twitter Feed
Top Comments of the Week