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.