USB power supply active load tester
Sasa Karanovic has designed and built a DIY USB power Supply active load tester, that is available at GitHub:
USB Power supply Active Load Tester or short PAL Tester is unit designed for testing the quality of the power supplies.
Idea was to create low-cost, precise device for simultaneous measurement of Voltage and Current drawn from the device under test.
USB power supply active load tester – [Link]