Recent content by leafy

Yes, I'm only interest in something new. I find that the argument against Maxwell's demon is a little short. I also read Feyman's ratchet.

Suppose we have a cylinder with one wall guard by a demon. Inside is one gas molecule moving left and right for simplicity. Now we want to closer the wall (compress the gas) without doing work. The job of the demon is push the wall closer when the gas move left and lock the wall when the gas...

Net current = 0

I think solid state is harder.

But there is current through it. Each time the switch close, current flow to speed up the wheel. Each time current flow to the 24V, curren flow slow down the wheel. Each cycle, there is a speed up and slow down. The net is zero current with is steady state.

Unload motor require current to overcome friction. Loaded motor require current for the load. We assumed ideal, no friction, so the only requirement is current for the load.

I do not get what you mean. How is it not zero?

Hm... you might have read the diode wrong. The bottom 24V has diode that only allow current for charging direction . The bottom 24V cannot be the supply. When the switch close, current is draw from the 12V through the coil, speeding up the wheel. Then the switch open, it'll close again on...

The current input has to be equal to current output have steady state speed. If there is only input current, the wheel would keep speeding up. And when we draw output current, that is a load. Charging battery is a load.

Base on the replies I think the answer is yes. Let's assume that everything is ideal. The current going into the magnet - current induced by magnet = 0 for steady state. Let's assume all batteries are 12Vs. So from the input we have IV = current of 12V x 12V = Power input From the output...

Tell me if this circuit possible. The switch close and open to spin the magnet. The magnet attain enough speed to charge two batteries in series.

Well, my main purpose is to see if we can attain an EMF greater than the supply voltage. When the magnet pass by the coil, let's say it's supper fast that exceed the supply voltage, we aren't apply voltage to the coil because if we do, the magnet slow down in transfering energy to the supply...

Yes, I guess we have to assume the coil can be on instantly without being choke. What I'm trying to say is can we attain EMF greater than the supply voltage.

As I drew in the voltage waveform, when the magnet change direction from incoming to outgoing, the back EMF is so small that we can inject current into the coil. Of course the wave form get bigger as speed increase, so we have to shorten the ON time of the coil. But we can always inject...

I read that the factor that limit motor speed is back EMF. I might have to go to an electrician for this one.