So yeah, I'm trying to get some more voltage/amperage from the GPIO pins on my Raspberry Pi 2 Model B. I've ran several tests and I'm only getting about 3.2V and 30-40mA. This cannot do much, there must be a way that I can somehow get some more power, probably through an external power source such as a battery. I've heard some things about sending small electrical signals to make something like this work.
The only problem with this is that I've no idea how I can do this, which is why I'm asking this question.
I want to do things such as lighting up a light bulb or something related to that, 3.2V and 30-40mA just isn't gonna cut it. A 9V battery, on the other hand, can easily power something like this.
Thank you for any help, it is much appreciated.