ACS712 Hall-Effect Current Sensor

Read DC and AC current up to ±5 A through an isolated Hall sensor — no shunt, no series resistance, no ground loop.

Difficulty: Breadboard. Estimated build time: about 40 minutes. Estimated parts cost: about US$4.00. 7-part bill of materials with live supplier pricing. A current meter that puts no resistance in your circuit and is galvanically isolated from the load.