USB Charger Doctor

Use the USB Charger Doctor to measure the working voltage and current output for any USB port and project. This dongle plugs between a USB device, and passes the data lines through. There's a 0.05 ohm resistor in line with the power pin that is used to measure current draw. The Doctor's digital display instantly reads the numbers out for testing devices such as chargers, cables, and cell phones. You can use this device from 3.5-7VDC input voltage (although most USB devices tend to hover around 4.75 to 5.25) and up to 2.5A of current.