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 Wednesday, August 17, 2011 |
Some geeks get excited about a new phone or computer. Let me tell you about an interesting new technology that gets me going. Actually, the company that makes this technology, Melexis, has quite an array of different and interesting sensor chips. The one that got me interested was their MLX91206.
 This chips is an 8 pin surface mount chip. It is a Hall sensor chip. The Hall effect can be used to measure a magnetic field. A magnetic field is generated by an electric current. Thus this chip can be used to measure an clectric current or any magnetic field. Its very sensitive to magnetic fields at right angles to the chip. So you can run a conductor under (or over) the chip and measure the current in that conductor. Multiple N passes of the current (like with a winding) would generate N times more magnetic field and make the chip N times more sensitive.
It is very sensitive, offers isolation, and most importantly is programmable! That right it can be programmed to different gains, or a PWM output proportional to the field, or an ON/OFF output!!!! The On/Off threshold is also soft.
I have found two caveats. The first is that it is so sensitive that you need to be concerned about stray magnetic fields. The second is the programmer from Digikey costs $1500. This is a stiff barrier to using the chip if you ask me. But on the plus side, the chip is usable in analog mode without programming it, and there are several other analog versions of the chip that also do not require programming.
Want to read about the Hall effect and its' discoverer? |
damon at 9:33 AM |
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