Synchronous Brushless Alternator for Free Energy?

It is impossible to do what the YouTube video shows. That is a fraud. There are friction losses, electromagnetic losses and resistance losses in the bearings and wires in both the motor and the generator and the loads connected to the system. As the power draw increases, electromagnetic resistance increases. It it were possible, that would have been done late in the 19th century. The electromagnetic resistance is the concept behind regenerative braking on some automobiles, roller coaster rides (at the end of the ride) and other similar systems. But if you can connect a 5 ton flywheel and get it spinning at a high rate, the inertia will allow you to run an alternator for several minutes, maybe up to an hour and drive an alternator. But takes energy to get that flywheel up to speed.

1. Running a cycle on brushless outrunner motors? [closed]

Let's assume you do a motor on the crank shaft rather than on the hub.When you step on the pedal/crank it's approximately the mass of your body doing all the work.$Torque(tau)=Force*Distance$, $Force=mass*Acceleration$$mass:=70Kg$, $Acceleration:=9. 8fracms^2$, $Distance:=0. 2m$$tau=70times9. 8times0. 2 implies140Nm$ of torque for a motor to provide the same torque that you do.$Power=Torque*Speed(in fracradianssec)$ Cranking the pedals a full turn each second is reasonable.$1fracrotationsec=frac2pispace radianssec=frac6. 28space radianssec$So, $140Nmtimes6. 28fracradianssecimplies 880Watts$This is a peak, you would get tired very quickly pedalling this hard, (think about how long you can climb stairs at 2 per second). Average human power is closer to 100W.So now you have some numbers. You do not need more than 140Nm peak torque, and around 900W power. (Laws usually restrict you to less than this power). Let's say that you just want some power assist. 30Nm and 50W of power might be ok.I have no idea which motor you were looking at; here's one at random in the 30 range. Let's estimate the torque it will produce. The motor constant kv tells us a lot. Not only is it an estimate of the backemf (ie how many volts per rpm the motor generates when it's spinning), the inverse of the same consant is an estimate of how much torque per amp is produced.$kvimplies fracVoltsfracrotationsminimpliesfracVoltsfrac2pispace radians60secimpliesfrac602pifracVoltsfracradianssecimpliesfracVoltsfracradianssec=frac2pi60kv$$fracVoltsfracradianssec=frac1fracNmAmpimpliesfracNmAmp=frac1fracVoltsfracradianssec=frac602pi kv$That motor has a kv of 335$fracrpmV$ so it's torque constant is about .028$fracNmAmp$ and it has a max current of 28A so it's maximum torque is 0. 78$Nm$So you would need around 40:1 gearing to get the torque into the range we want. So even though the motor seems to have enough power, to amplify the torque to be useful, you will need gearing. A company I've been happy with and is relatively cheap is golden motor

2. Differences between brushed and brushless motors - advantanges and disadvantages of each

At first brushed are fine because they are cheap and easy to replace. The more you read about specs and tuning you will take interest in brushless. For example betaflight now has rpm filtering which allows the gyro to reduce interference based on the rpm of the motors. So above tinywhoops and toys you are going to be seeing brushless

3. Can someone please explain brushless motors, esc's, and lipo batteries to me? (in relation to rc cars)?

Hi Jess the brushless motor has a small circuit board attached which converts a Direct current supply to 3 phase alternating current so they are AC motors. As to the other items i will watch to see the explanations given by others.

4. Brushless DC motor steady-state performance modeling

This is true for stepper motors and PM synchronous motors powered by AC, but PM BLDC motors usually have their commutation controlled by Hall sensors or back-emf zero crossings. So it is the speed/current/torque of the motor itself which determines the commutation frequency - same as in a brushed DC motor. The formulas for brushed and brushless DC motors are the same. Yes, however 'hobby' motor constants are often not very accurate, and using them can result in quite large differences between calculated and actual performance

5. A4963 3 Phase Brushless Sensorless

You will also need to configure the part using an SPI interface from your processor and a sense resistor to sense the current. The parts are very easy to use. I would recommend the eval board - it will run most motors out of the box and they provide a PC interface to try different configurations