I wanted to power a USB device from the D-Tap adapter on the back of my broadcast camera.
I turned to Amazon and found this.
Features: Smartphones, monitors and BMCC can be powered by the adapter when D-tap 2 pin male input connects with V-mount battery. Monitors and BMCC can be powered by the adapter's D-tap 2 pin female output. Smartphones can be powered by the adapter's USB port. Power Input (Standard Male D-Tap): 11~17V 10A(Max) Power Output (Standard Male D-Tap): 11~17V 10A(Max) Power Output (USB): 5V 1.6A(Max)
Specifications: Brand: ROLUX Model: D-USB Compatibility: For smartphones, monitors and BMCC Item Weight: 23g / 0.82oz Package Size: 6 * 4.6 * 2cm / 2.4 * 1.8 * 0.8in Package Weight: 26g / 0.92oz
Package List: D3705 1 * D-Tap to 5V USB Adapter