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Just got through reading this patent by the Algoforce guys:
AU2024201955.pdf
It seems to focus on methods for minimizing the output offset of the demod which, I assume, they are concerned with for non-motion pinpoint mode. In one claim they inject a current into the feedback of the opamp to zero the output offset. I don't understand how anyone could get a patent on this as this has been commonly done for decades. It's even specifically been done in metal detector demods; the Fisher F-Pulse pinpointer does it.
But the real curiosity is the method of using an underdamped response along with positive/negative sampling to zero the output offset. This will work, but it means that the target signal is largely canceled in the process. Even with an underdamped response where the decay has a positive portion and a negative portion, both portions are deflected in a positive direction by a target. A +/- double-sample as in Fig. 6 will mostly cancel the response unless the response is so fast that it mostly falls inside the (+) sample, probably true only for super-tiny nuggets. Am I missing something?
moodz: Unrelated question: When I search for patents on IP Australia quite often there is no way to download the patent or the application. For example: https://ipsearch.ipaustralia.gov.au/patents/2008904471. Why is this?
AU2024201955.pdf
It seems to focus on methods for minimizing the output offset of the demod which, I assume, they are concerned with for non-motion pinpoint mode. In one claim they inject a current into the feedback of the opamp to zero the output offset. I don't understand how anyone could get a patent on this as this has been commonly done for decades. It's even specifically been done in metal detector demods; the Fisher F-Pulse pinpointer does it.
But the real curiosity is the method of using an underdamped response along with positive/negative sampling to zero the output offset. This will work, but it means that the target signal is largely canceled in the process. Even with an underdamped response where the decay has a positive portion and a negative portion, both portions are deflected in a positive direction by a target. A +/- double-sample as in Fig. 6 will mostly cancel the response unless the response is so fast that it mostly falls inside the (+) sample, probably true only for super-tiny nuggets. Am I missing something?
moodz: Unrelated question: When I search for patents on IP Australia quite often there is no way to download the patent or the application. For example: https://ipsearch.ipaustralia.gov.au/patents/2008904471. Why is this?
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