So power is precious and power is the problem with all VTOL aircraft. No matter how cool batteries are and how important fossil fuel reduction is, if we want massive acceptance of VTOL Cars, we need long range & fuel consumption. We need the big oil to be our friends….. even if you don’t love the idea.
To start on a small scale, we are going to try and get this drone running on fuel. YEAH! FUEL! So where the heck do we start? Keep in mind a big ole dummy and a novice in this space. Let’s look at the problem.
The drone runs on batteries. 4S LIPO is a decent start. This is 14.8VDC. I just ran a 2250 mAH capacity for about 4 minutes give or take. What power draw is this? 2250 is 2.250 aH which 4 minutes is 0.066 hours so 2.25aH/0.066H = 34 amps at 14.8VDC ish which is 34*14.8 = 503 W.
What tools can you have log power consumption on drones? – It looks like the Pixhawk flight controller has variables that should be logging this but without telemetry reading back, I don’t know how I’d access this. Something to come back to and will be necessary.
For the moment, let’s assume I need about 50 Amps at 15 volts produced, seems like a freaking crap ton. Also, is this generator going to charge a battery and then that battery run the system? How does the charge and discharge work? This is 750 W… This sniff tests like a ton of power? I guess it is reasonable that it would be a crap ton of power considering this would be a forever running drone….. kinda cool.
General Idea:
Spin a DC Motor with a gear ratio and high revolutions to output voltage. (Credit: https://www.youtube.com/watch?v=tb3iN4m9Bik)
So for about an hour I’ve been researching and I’ve learned that I have no idea what’s going on so I’m going to start by re-creating Tom Stanton’s build above. He seems like a cool dude. Hopefully re-creating will teach me a little more.
Building an alternator – Definition: An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature
So I read a bunch about it and seems plausible with a rotor (our 2) around a stator. The stator has a certain amount of wires coiled and then the rotor has the magnets. The magnet’s movement around the coil creates the electric field. Because the current direction changes, a bridge rectifier will transform the AC into DC. To keep things filtered and smoother, capacitors can be added.
I don’t seem to have the right stuff so this will have to be continued. On an unrelated noted, the idea was to have fuel to power the generator and the generator to charge batteries. On a small scale, this looks complex and expensive. RC jet engines could be the best route but at that rate, why not just have jet engines instead of brushless DC motors? Sounds fun to me, one thing at a time I guess.
