what choices are available for current sensing

[seyyah]

What can we use for current sensing instead of simple resistor both in ac and dc which is more accurate and reliable than resistor yet cost effective?

 

[electronrancher]

resistor is most accurate by far (1-5%) but wastes power. inductor (DCR) current sense is accurate to about 20%. internal mosfet is accurate to about 30% and external mosfet is as bad as 100%.

 

[Ante]

seyyah,

You don’t need any resistor; just use a part of an existing wire that’s all.

Ante :roll:

 

[alex840]

Your can try Hall-effect current sensors.
**broken link removed** for example.
They are quite expensive, but quite useful.

 

[FoxyRick]

Take a look at Allegro's offerings here:

**broken link removed**

They look good; I have a few samples but have not used them in a live design yet. They are easy to get samples from.

Quote from site:
The ACS750 and ACS752 family is the latest in innovative, integrated solutions from Allegro MicroSystems and the first step in a new revolutionary line of fully-integrated in-circuit current sensors. This unique current sensing assembly includes an ultra-low resistance, high-current conductor, magnetic concentrator, and an optimized monolithic Hall IC in a convenient and compact package. Applications include, but are not limited to: motor control, load management, switched mode power supplies and over-current fault protection. The ACS750 and ACS752 family is especially suited where electrical isolation from the sense circuit and power circuit is required.

Cheers,
FoxyRick.

 

[bunalmis]

What can we use for current sensing instead of simple resistor both in ac and dc which is more accurate and reliable than resistor yet cost effective?

You can use dc current transformator. This is expensive. (Use resistor)

https://www.directindustry.com/