Fun fact: when the audio cassette industry faded, some companies producing the magnetic tape needed to reinvent themselves. Therefore, they used a very similar technology to become the main providers of magnetic scales for encoders. The working principle is quite close actually even though the encoding of the position is different and in this case the 'reading head' is a more advanced triaxis hall sensor.
- Absolute or incremental? I'm guessing absolute, looking at the "Vernier" arrangement of the poles at 2:14. - How about (in)sensitivity to radial displacement? - Where does one procure the patterned (ring) magnets? -Readout speed? What peak-angular-speed is legible?
- Good guess. The encoder is absolute. - Due to the bigger size of the Master track which is providing the accurate angle, the effect of the crosstalk coming from the Nonius track is reduced with consequent improved robustness against radial wear-out (which normally causes crosstalk variation). - Magnet can be customized according to specific design rules. Distribution strategy is still being defined. - Noise performances are specified for 1ms refreshing rate. For intermediate product, readout period is 80us. For the final product it will be possible to readout angle and speed at periods as small as 15-20 us.
@@BrunoBrajon Thanks!! Is there a limit on the angular speed of the rotor? A dentist's drill (for example) runs at ~100k RPM i.e. ~1e4 rad/s. I can imagine that the sensors might have trouble reading the angle (albeit with aliasing) as the rotor-magnet would travel almost 50 deg in an 80us window.
@@AdityaMehendale The sensor includes look-ahead angle correction for very high-speed applications. The maximum speed of rotation the sensor can work at depends on the number of pole pairs on the Master track. In general Max rotation speed is equal to 200krpm/Number of polepairs on the Master track. With the magnet shown in the video, this is equal to 25 krpm
Why aren't encoders made with magnetic tape and tape reading heads, like in audio cassettes?
Fun fact: when the audio cassette industry faded, some companies producing the magnetic tape needed to reinvent themselves. Therefore, they used a very similar technology to become the main providers of magnetic scales for encoders. The working principle is quite close actually even though the encoding of the position is different and in this case the 'reading head' is a more advanced triaxis hall sensor.
- Absolute or incremental? I'm guessing absolute, looking at the "Vernier" arrangement of the poles at 2:14.
- How about (in)sensitivity to radial displacement?
- Where does one procure the patterned (ring) magnets?
-Readout speed? What peak-angular-speed is legible?
- Good guess. The encoder is absolute.
- Due to the bigger size of the Master track which is providing the accurate angle, the effect of the crosstalk coming from the Nonius track is reduced with consequent improved robustness against radial wear-out (which normally causes crosstalk variation).
- Magnet can be customized according to specific design rules. Distribution strategy is still being defined.
- Noise performances are specified for 1ms refreshing rate. For intermediate product, readout period is 80us. For the final product it will be possible to readout angle and speed at periods as small as 15-20 us.
@@BrunoBrajon Thanks!! Is there a limit on the angular speed of the rotor? A dentist's drill (for example) runs at ~100k RPM i.e. ~1e4 rad/s. I can imagine that the sensors might have trouble reading the angle (albeit with aliasing) as the rotor-magnet would travel almost 50 deg in an 80us window.
@@AdityaMehendale The sensor includes look-ahead angle correction for very high-speed applications. The maximum speed of rotation the sensor can work at depends on the number of pole pairs on the Master track. In general Max rotation speed is equal to 200krpm/Number of polepairs on the Master track. With the magnet shown in the video, this is equal to 25 krpm
Great informations, @arduinomaquinas thank you man, subscribed 😊🇧🇷👏👏👏👏👏👏