Hey, I am working on a science fair project and I have an electrolytic cell that will produce hydrogen. My goal is to measure the energy input and output to calculate the efficiency of the cell. Right now I am trying to find the best way to calculate the input energy. I am in the process of building my own power supply for the cell that I have already built and need an accurate way to measure voltage and current. Right now I have an old microwave oven transformer that I rewound for about 40 volts that gets rectified. Now I need to know what is the best way for me to measure the power and eventually energy that I am putting into the cell. I think that I can smooth the rectified signal and measure it with normal moving coil meters but I am not sure if that will throw off my calculations. Ive been looking into peak detectors and other circuits that may be useful to detect voltage and current if I leave the signal rough (The electrolytic cell doesn't need smooth dc). Any help would be much appreciated. Oh and the if you are curious to measure energy input and output i will measure the average power over a certain amount of time as well as the amount of gas produced in the same time span. I believe this is the correct way to measure it.