I received this 3.3V or 5V power supply. It's neat because it fits on my breadboard and can provide two separate voltages (chosen using jumpers) on it's two outputs. I originally thought that this was a Step-Down Converter, however, it's been pointed out to be a Linear Regulator.
Here, I have the left-hand side providing 5V, while the right-hand side provides 3.3V. I've used my multimeter to verify it working from a 9V battery.
I am curious what the jumpers in the middle of the board will do. There are two 5V->GND, and two 3.3V->GND. I've made attempts to find information about this specific device, but I haven't found any identifying information, nor have I found any information about it online.
I'm afraid to use this for longer than looking at the voltage on either side because I am unsure the purpose of these jumpers, or if/when they should be bridged for safe/normal operation.
Any help identifying and understanding the purpose of these jumpers in the middle of this device would be greatly appreciated.
Best Answer
The 4x2 header in the middle is there for you to access the voltage rails and Ground with female jumper wire or test clips or whatever. It's for your convenience.
And no, that board does not function as a step up regulator. It's not even a step down switching regulator. It is just two linear regulators.