Out-of-phase detectors produce two pulse signals that indicate relative rotation as well as direction for an incremental encoder. Counting edges or monitoring binary values can increase resolution fourfold.
I hope to see more of the Wiegand effect encoders in the near future. It might be a good alternative to optical encoders in a closed loop stepper motor system. Which, by the way, are getting cheap enough for anyone to buy.
Great article - I particularly liked the mention of using hall effect sensors. Makes sense since historically they have been used as rotary position gear tooth sensors such as crank and camshaft sensing in automotive applications. They are usually a lot cheaper than optical encoders too.
Hello, TJ. As far as I can tell, the magnetic field for a Wiegand detector must be very localized, so magnetic interference shouldn't become a problem. Resolvers get used with equipment that uses electric motors, so I bet the manufacturers have added shielding as needed. Worth asking about before you buy a resolver, and worth the time to run some tests in proximity to specific equipment.
In my applications, I often need an axis with a hollow bore, so the position encoder either needs to be hollow. From what I can tell, the Wiegard effect only works when the rotating magnet axis of rotation is centered about the Wiegard wire. I'm sure I've misunderstood the tech in some way and hope that my understanding is wrong.
If my understanding is wrong and the axial rotations do not have to align, then I'd be inclined to merge an optical absolute encoder with a Wiegard sensor for counting rotations. You'd get the resolution of optical with the persistent turn counting of the Wiegard sensor.
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
In 2003, the world contained just over 500 million Internet-connected devices. By 2010, this figure had risen to 12.5 billion connected objects, almost six devices per individual with access to the Internet. Now, as we move into 2015, the number of connected 'things' is expected to reach 25 billion, ultimately edging toward 50 billion by the end of the decade.
NASA engineer Brian Trease studied abroad in Japan as a high school student and used to fold fast-food wrappers into cranes using origami techniques he learned in library books. Inspired by this, he began to imagine that origami could be applied to building spacecraft components, particularly solar panels that could one day send solar power from space to be used on earth.
Biomedical engineering is one of the fastest growing engineering fields; from medical devices and pharmaceuticals to more cutting-edge areas like tissue, genetic, and neural engineering, US biomedical engineers (BMEs) boast salaries nearly double the annual mean wage and have faster than average job growth.
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.