Electronic enthusiasts looking for a way to control power to the next project from a 9 V battery may be interested in a small device called snapVCC. Available to purchase from the Crowd Supply website from just $15 with worldwide shipping available from $12.
The small connector offers a highly portable and convenient power supply for your electronic projects and has been specifically designed to fit directly on top of a 9 Volt battery. Providing you with 3.3V or 5V power wherever you need it. snapVCC uses a buck converter for efficient regulation of battery voltage. snapVCC has an LED power indicator, reverse polarity protection, and you can switch between 3.3V and 5V by just switching a jumper.
“Many circuits require a regulated 3.3 or 5 volt power supply. The 9V battery is an easily available power supply option. A common way to power circuits using a 9V battery is to use a Linear regulator IC circuit to drop the voltage down.”
“snapVCC eliminates this additional circuit by putting the regulator right on top of the 9V battery.Also, since snapVCC uses a buck converter, it’s more efficient than using a linear regulator. In an emergency you could even charge a simple (non-smart) phone with snapVCC.”
Specifications of the snapVCC include a Texas Instruments TPS560200 buck converter with 500 mA output current, 3.3 V / 5 V output, switchable via jumper, P-MOSFET for reverse polarity protection, Power indicator low power LED, Tiny form factor, sits on top of a 9V battery, Power headers are standard .1″ pitch and Comes with a jumper cable for plugging into a breadboard.
Source : Crowd Supply