Using an operational amplifier, this circuit from a 90s Popular Electronics, is characterized by its high sensitivity. R5 can be added to control the gain.
The TSC102 integrated circuit from ST-Microelectronics consists of a current sensor system that, in...
This circuit was found in old documentation, but the transistor may be the modern equivalent BC547....
The IC used in this project is not common these days, but if you have one you can build a high...