The simple power supply is the power kit for you providing 5V, -9V, and 3.3V all from a single 9V battery. While power sources such as 9V and AA batteries can be used to power some kits directly not every kit can handle these unregulated voltages. For example, any kit with an active buzzer requires a 5V source and some other kits (such as the M602 Door Bell) can only handle up to 4V! Generating these voltages can be cumbersome and any project that requires more than a single 5V source may prove challenging. This is where the Simple Power Supply comes in! This kit is directly powered from a 9V battery and provides many different outputs.
This kit generates the 3.3V with the use of the AMS1117 which is an SMD part. However, this is a very easy component to solder (arguably one of the easiest SMD parts to solder) and can provide great soldering practice for surface mount devices!

Instructions / documentation
What’s in the kit?