HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
  |  REGISTER  |  LOGIN  |  HELP
<<  <  Page 3/5  >  >>
armorris
User Rank
Platinum
Re: Handy project!
armorris   9/21/2012 12:09:00 PM
NO RATINGS
The PICLIST forum has gotten so huge now, that I find it almost impossible to find whatever help I need. It was a big help to me years ago, when I was first learning about PICs.

 

armorris
User Rank
Platinum
Re: Monitoring back EMF?
armorris   9/21/2012 12:03:05 PM
NO RATINGS
Yes, it measures the back EMF after momentarily disconnecting the motor. This scheme would not work with a universal motor. You need to use IR compensation for that kind of motor. The analog version of this gadget, referenced in the article, uses IR compensation. A scaled-up version of that circuit would work fine with a universal motor, like the Dremel Moto-tool.

Also, why do you need to have extremely high speed for working on hearing aids. A Dremel moto-tool runs extremely fast without boosting the voltage. I'm afraid to do delicate work at high speed. Do you know something I don't? High speed would melt plastic parts.

Nancy Golden
User Rank
Platinum
Re: Handy project!
Nancy Golden   9/21/2012 11:26:24 AM
NO RATINGS
What a cool looking kit, mrdon - that looks like a lot of fun. Thanks for the link, it makes me want to start playing with my PIC stuff again. Another thing I love about using Microchip products is the technical support that is available, their extensive documentation of their PICs, and their forum community. I have gotten some excellent help when I was stumped on a project that I was contracted to do and wound up making a great friend and partnering on the project with him that (speaking of patents) was eventually patented by the company we wrote the code for.

mrdon
User Rank
Gold
Re: Handy project!
mrdon   9/21/2012 11:15:33 AM
NO RATINGS
Nancy, I agree PIC projects are really cool and fun to build. In reading Andrew's Build document, the assembly language code used to monitor and control the motor is quite typical of Microchip. All of their microcontroller software reference design documents illustrates the target application with assembly code. Here's a link for a cool PIC Lab Development kit including the PIC10F microcontroller.

http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en539716&redirects=picdemlab

DanSchwartz
User Rank
Iron
Monitoring back EMF?
DanSchwartz   9/21/2012 10:54:46 AM
NO RATINGS
Looking at the patent application but not yet seeing the schematic, are you monitoring the back EMF after shutting off the voltage?

Also, will this only work with universal motors because you're feeding it PWM'd DC?

I use a 500 VA variac for my Dremel grinder speed control, as there are times when I want to boost the voltage to 140VAC for extra speed while performing some delicate grinding on hearing aids.


Dan Schwartz,

Editor, The Hearing Blog

http://www.TheHearingBlog.com

rScotty
User Rank
Silver
Re: Patent issues
rScotty   9/21/2012 10:45:53 AM
NO RATINGS

What a clever controller, Morris!

This discussion of the patent process is remarkably similar to what I experienced while doing engineering technical consulting for large corporations.....right down to the description of the witnesses and the many co-inventors. 

I was routinely asked to evaluate patents for useful information. Often this evolved into equally simple ways in which the whole patent could be subverted.

Without offering any moral judgment, I'll simply note that my engineering career spanned enough years to see what was once ethically questionable becoming a common and valued engineering practice. 

It may be at a patent was never as much of a strong protection in reality as it was in folklore. How could it be wit such a low level of international support?

My advice to startups is not to assign too much importance to patents. Lack of a patent should not be the deciding factor. It may be that more businesses failed to get started from fear of not having a patent than ever failed from patent challenges.
In my opinion, the real value of the patent process is in the way that it promotes education and advances knowledge.

I would like to see the patent process continue evolving away from it's legal and protective roll and more towards becoming a vehicle for recognizing unique achievement and distributing new ideas.

  Roger L.   (rScotty)


Noswad
User Rank
Gold
Re: Handy project!
Noswad   9/21/2012 10:40:07 AM
NO RATINGS
Wow! That's a pretty expensive add on to a $10 piece of junk china tool.

Sorry, but I just don't see it being worth it for this tool.

armorris
User Rank
Platinum
Re: Handy project!
armorris   9/20/2012 4:20:07 PM
NO RATINGS
One of the things we did at the R&D center was break other people's patents. We worked with the lawyers to find loopholes to use ideas that we wanted. This was not the fault of my former employer, but is common practice in big business.

So, yes Nancy, we did exactly what you're talking about. We would make some small change to get around the patent.

Nancy Golden
User Rank
Platinum
Re: Handy project!
Nancy Golden   9/20/2012 4:03:15 PM
NO RATINGS
I looked into it with my portable trail obstacle small business (no one makes portable trail obstacles and hubby and I do all of the design work). We ended up just using a trade mark symbol for the phrase "portable trail obstacles" which would give us some ownership rights depending on what state you are in...and we could have done a patent pending for a small fee without actually going through the trouble of getting a patent - but as you said, it would be whoever had the deepest pockets would have control. Just not worth pursuing for a business run out of a tiny home office. Also, people can tweak their design enough for a patent to be issued to their design even if it was originally copied from yours...

armorris
User Rank
Platinum
Re: Handy project!
armorris   9/20/2012 3:31:33 PM
NO RATINGS
It's a shame to have to say it, but IMO, patents are no longer a viable option for the individual, except in rare cases. I just wanted to stir up some conversation on the subject and see what came out of it. I also wanted to tell my story about what happened to the patent on my invention, which is being used in this gadget. 

<<  <  Page 3/5  >  >>


Partner Zone
Latest Analysis
Researchers in Canada have developed a chin strap that harvests energy from chewing and can potentially power a digital earplug that can provide both protection and communication capabilities.
In case you haven't heard, the deadline to enter the 2014 Golden Mousetrap Awards is coming up fast Oct. 28! Have you entered yet?
Made by Monkeys highlights products that somehow slipped by the QC cops.
A Tokyo company, Miraisens Inc., has unveiled a device that allows users to move virtual 3D objects around and "feel" them via a vibration sensor. The device has many applications within the gaming, medical, and 3D-printing industries.
In the last few years, use of CFD in building design has increased manifolds. Computational fluid dynamics is effective in analyzing the flow and thermal properties of air within spaces. It can be used in buildings to find the best measures for comfortable temperature at low energy use.
More:Blogs|News
Design News Webinar Series
9/25/2014 11:00 a.m. California / 2:00 p.m. New York
9/10/2014 11:00 a.m. California / 2:00 p.m. New York
7/23/2014 11:00 a.m. California / 2:00 p.m. New York
10/7/2014 8:00 a.m. California / 11:00 a.m. New York
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Oct 20 - 24, How to Design & Build an Embedded Web Server: An Embedded TCP/IP Tutorial
SEMESTERS: 1  |  2  |  3  |  4  |  5  |  6


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: October 2
Sponsored by Altera
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service