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How to read output across a 2-wire DC magnetic or hall effect sensor? Also my requirement of switching frequency is 1000 Hz, but most of the sensors out there have a maximum switching frequency of 5000 hertz. Will this affect accuracy when I measure low frequencies?

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  • \$\begingroup\$ Are you saying the limit speed of activating and deactivating a hall sensor (you have found) is 5000 Hz? \$\endgroup\$ – Andy aka Feb 2 '14 at 19:00
  • \$\begingroup\$ yes 5000hz is the limit speed of activating and deactivating a hall sensor. \$\endgroup\$ – user36524 Feb 2 '14 at 19:09
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If the Hall sensor can be triggered as fast as 5kHz then operating it at 1kHz shouldn't really be a problem. Hall sensors work all the way don't to DC and are designed to have a flat frequency response. I'm supposing that the Hall sensor you have considered has a digital output from the way you've couched the question. You need to read its specification to see what supply voltage it needs and what pulsing output voltage it produces. Then you need to ask yourself what it feeds into (your circuit) and if the signal levels are compatible then there should be no problem.

If you want more detail in the answer you have to give more information in your question.

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  • \$\begingroup\$ What I actually want to know is that how to get the voltage output from the 2 wires of the sensor. I have seen some examples in which a load is connected across the positive or negative wire depending on whether the sensor is sinking or sourcing, if so then what load I should use. I need to feed the output to GPIO pin of a microcontroller and i will read the rpm by sensing the frequency of sensor output. I am using a 5V sensor, so output voltage will be compatible with my microcontroller. \$\endgroup\$ – user36524 Feb 2 '14 at 19:40
  • \$\begingroup\$ @user36524 I need to know what sensor you are considering or I'm just generalizing and maybe missing a trick associated with the specific sensor you have in mind. \$\endgroup\$ – Andy aka Feb 2 '14 at 20:07
  • \$\begingroup\$ This is the datasheet of the sensor i plan to use docs-europe.electrocomponents.com/webdocs/0027/… \$\endgroup\$ – user36524 Feb 2 '14 at 20:11
  • \$\begingroup\$ Sir please answer my question, i need to know that how should i connect this 2 wire sensor to my microcontroller to observe its voltage output giving it a 5V supply. \$\endgroup\$ – user36524 Feb 2 '14 at 21:38
  • \$\begingroup\$ It can run from a 5V supply and that's all I can tell from the data sheet you linked. I'd guess that it needs two wires and that the current drawn is 2mA when activated by a magnet and 0.7uA when the magnet isn't there. You probably need to use a voltage regulator like a 7805 and a voltage feed to the regulator that you can monitor the current of using a series resistor BUT that's reading between the lines. I'd contact the supplier. Sorry i can't be more useful. \$\endgroup\$ – Andy aka Feb 2 '14 at 21:48

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