Breaking News
Comments
Newest First | Oldest First | Threaded View
hithesh
User Rank
Rookie
re: Simple circuit measures RMS value of AC power line
hithesh   11/10/2012 10:47:06 AM
NO RATINGS
I actually thought this article would explain how you get RMS output from AC. Nothing useful in this article.

grouts
User Rank
Rookie
re: Simple circuit measures RMS value of AC power line
grouts   11/9/2012 5:22:08 PM
NO RATINGS
The above circuit and thesis is reasonably OK. A couple of things not included in the above engineering are: - loss of course in the line/circuitry leading to the above measuring circuitry, including to the two resistors. - The thermo properties of the two resistors being heated by the signal-under-test and the DC signal. You have to, of course, also include the TRANSIENT thermo properties of both (I never did trust DC, including the wiring to/from the power supply.) By the way, I believe your above circuit, including it basic premise, is covered by a patent taken out by Norm Dillman while at HP. Myself, I used similar circuit approaches as this to provide thermal biasing stability on the many class B power amplifiers I designed for GE Audio Products back in the 60's. But you have a nice circuit as well as a nice paper describing it and your engineering. --Steve Grout



EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Glen Chenier

Engineers Solve Analog/Digital Problem, Invent Creative Expletives
Glen Chenier
2 comments
An analog engineer and a digital engineer join forces, use their respective skills, and pull a few bunnies out of a hat to troubleshoot a system with which they are completely unfamiliar. ...

Max Maxfield

What's the Best Traveling Toolkit?
Max Maxfield
17 comments
A few years ago at a family Christmas party, I won a pocket knife as part of a "Dirty Santa" game. This little scamp was a Buck 730 X-Tract. In addition to an incredibly strong and sharp ...

Rishabh N. Mahajani, High School Senior and Future Engineer

Future Engineers: Don’t 'Trip Up' on Your College Road Trip
Rishabh N. Mahajani, High School Senior and Future Engineer
10 comments
A future engineer shares his impressions of a recent tour of top schools and offers advice on making the most of the time-honored tradition of the college road trip.

Larry Desjardin

Engineers Should Study Finance: 5 Reasons Why
Larry Desjardin
41 comments
I'm a big proponent of engineers learning financial basics. Why? Because engineers are making decisions all the time, in multiple ways. Having a good financial understanding guides these ...

Top Comments of the Week
Flash Poll
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)