Cutting your household’s energy use means knowing exactly how much energy you’re using in the first place. This is something that can be done with the help of a simple energy meter – a device that sits between the appliance in question and the wall outlet.
Energy monitoring will not only help you to save money. It will also reduce your impact on the environment, and help you to safeguard the natural world. There are a number of off-the-shelf devices that will help you to do this safely. But if you are comfortable dealing with mains voltages, and you have a background in electrical engineering, then you might elect to build a simple meter yourself.
Components and Tools Required Gathering Necessary Materials
If you want to track the watt-hours you’ve consumed, then the simplest solution is often a microcontroller embedded into a prototyping board like an Arduino. You’ll also need a way to display the information. This might mean a simple LCD screen, or perhaps a WiFi-based database that you can access remotely using your smartphone.
You’ll also need a current sensor and a voltage sensor, as well as an enclosure that will keep everything shielded away. Digital ammeters can do the job brilliantly. The enclosure can be made using a 3D printer, or it can be crafted from sheet timber using a table saw and pocket-hole screws. Depending on the design you choose, you’ll also need resistors, capacitors, and transistors of various values.
Assembly and Calibration Constructing and Testing the Energy Meter
Since we’re dealing with mains voltages, you might consider it safer and easier to download the schematics for a ready-made PCB. This will help you, for the most part, to avoid the hassle of soldering the board yourself. On the other hand, you might elect to get everything soldered yourself.
It’s a good idea to create standoffs so that you can attach and detach the microcontroller as you program it. You can find ready-made code that will help you get started, but if you’re looking to learn C yourself, this is the perfect project to get started with. Try to design the program such that you’re not taking readings constantly, and that you’re logging the data at fixed intervals.
You may have to calibrate the design when you’re done. This will typically involve placing a known load on the device, and then adjusting via code until you get an accurate reading. Placing two loads of different sizes might help you to make things still more accurate.
Once you’ve finished the device, you’ll want to attach it to an appliance whose energy consumption might be a problem for your home. Take a few readings from your refrigerator, and see how much energy it’s really consuming!