Re: [EE] Isolated AC line current sensors

Hi Harold,

My (sometimes) friend CGPT says a popular hall effect type current sensor is the 
Allegro Microsystems ACS37800, with internal shunt (models us to +/-30A), 
isolation, I2C/UART interface (ACS37002 has analog output if that suits better). 
Measures voltage too (I guess then the isolation reduces but can still be made 
appropriately safe) and calculates power etc. Looks pretty cool, nice to have all the 
essentials in one package.

Brent

On 21 Jul 2025 at 17:05, Harold Hallikainen wrote:
> I've been asked about sensing current on the AC line. Current transformers
> immediately come to mind. Also, I see there are Hall effect based sensors
> (similar to current transformers, but using a Hall effect device instead
> of a secondary winding). For isolation, I also see linear optocouplers,
> that have two photosensors so the LED current can be servoed. Another
> method would be a current sense resistor with an isolation amplifier.
> 
> I remember years ago an LTC RMS to DC converter that measured the
> temperature of a heater. It SEEMS like there could be a chip equivalent of
> a thermocouple ammeter with an electrically isolated heater and a
> temperature sensor.
> 
> Other ideas?
> 
> Thanks!
> 
> Harold