RE: DIY Loaded Voltmeter Help
It would be nice to have a constant current load so you could pick 500ma, for example, and no matter what voltage is across it, only 500ma is drawn. That would be nice, but is more complicated than what most people want to get into so they tell you to use a resistor. The current load will be the voltage (under load) divided by the resistance. So if you have a battery that under load gives you 7.4 volts and you put a 10 ohm resistor in across it while the voltmeter is connected, you get 0.74amp load or 740ma. So if you wanted a 500ma load then you want a resistor that is 7.4/0.5 that comes out to be 14.8ohm. Did that help? The problem with using a light bulb is the resistance changes as it heats up so a resistor is generally better. Make sure that the resistor can handle some power.....there is an easy way to calculate that as well....sorry if I told you something you already kenw.