hi guys,
i resurect this old thread because i was not able to acheive my goal : sense current in a led thread.
Your advices where very usesfull but I still have some problems sensing the current on the mosfet leg. In fact I have unstable values return buy the arduino when i sense the voltage from the output of the OPA. After searching, i think this can be linked to the switching frequency. Is that right ?
If yes do I have to set a low-pass or high-pass filter between the OPA and rsense ?
Docedison:
I would also give some thought to the Hall effect current sensors made by Allegro (ACH712) as they will produce a voltage that can be above Vcc/2 or below it at up to 185mV/amp, are inexpensive and don't require a sense resistor. All in all they are at first glance an ideal solution and work off of 5 volts too. I took the liberty of attaching a data sheet.
Bob
Did anyone know a Hall effect current sensor product (like the one Docedison told) but in DIP package ? I was unable to find this kind of device produced by those manufacturers: linear, allegro or maxim
Thanks for your time !
BR
