Anyone have a recommendation for a benchtop current sense amplifier?

Sure, there are current sense breakout boards and whatnot. But what I’d like is a convenient device that I can use to instrument a circuit and then monitor its current with my oscilloscope or logic analyzer (Saleae with analog input) along with other signals in the circuit.

Ideal features might be:

  • Banana jack inputs and outputs
  • Selectable range / sensitivity / sense resistor
  • Isolated measurement, so I can measure high-side or low-side currents without worrying too much about the common connection on my scope
  • Selectable or automatic power source selection, between circuit-powered and externally-powered

I haven’t seen anything like this in a few targeted searches, and just wondering if someone has any suggestions I might have missed.

  • eceforge@iusearchlinux.fyi
    2·
    11 months ago

    I mean what you are describing sounds like an exact match for oscilloscope current probes : https://www.digikey.com/en/articles/understanding-selecting-effectively-using-current-probes They are expensive, but convert AC and DC current to a voltage range reasonable for a scope and do so in an isolated manner. Bandwidth is basically as much as you are willing to pay for.

    For current shunts there is the EEVblog uCurrent but it’s not isolated, just a very low burden voltage shunt and amplifier essentially> https://www.eevblog.com/projects/ucurrent/

  • dragontamer@lemmy.worldMEnglish
    2·
    11 months ago

    As the other guy said: uCurrent is the one I knew about for general purpose use.

    There are specialist tools, such as Power Debugger for AVR / SAM (https://www.microchip.com/en-us/development-tool/ATPOWERDEBUGGER), specifically designed to handle the hundred-nanoamp level sleep currents of AVR devices, and still scale up to 100mA or so at relatively low bandwidths. But good enough for programmer / debugger / power-current-voltage measurements simultaneously and rather convenient despite its limitations and price.

    But Microchip / Atmel’s “Power Debugger” will only be useful to AVR, ATMega, ATTiny, and SAM microcontroller users. Its not too helpful outside of that environment.

    I’m actually building my own current measurement tool for this reason. Maybe I can post my design up and see if its useful to you?