I do wonder what the voltage curve looks like on that AC generator. White LED need about 1.7 volts to turn on? If the volts generated are only, say, 2 or 3 volts peak-to peak, then most of the energy is wasted. It might be best to have 6 LEDs: two red, two green, and two blue. The reds will turn on at .7 volts, the green at a slightly higher voltage, and then the blue. Also, the voltage when it spins down, then red will but the last to light.
I got a yellow colored version somewhere with a burned out bulb. It's at least 20 years old. I couldn't find a bulb to work in it so it got put aside. I wonder if a bridge rectifier and a dc to dc buck converter board to stabilize the voltage might make it run at a slower pumping speed?
I'm wondering, what if you were to out a cap in there and a switching buck-boost converter? That should basically make it rechargable by hand, no? And another question: ain't you afraid that the current will get too high for those tiny LEDs?
I've looked into adding rectifiers and caps, but I'm not convinced the losses are worth it. There are some ready-made ones that can be charged up, but I've found they are not efficient, and it takes a long time to get any charge stored up. The current coming out of the generator is tiny, it's the voltage that spikes. But if you look to see how they make LEDs extra bright, they pulse them on and off. The pulse on exceeds the LED's constant power rating, but turning it off allows it to cool. The LEDs are only on half the time, and they **might** exceed the voltage for only a fraction of the wave.
Great video, I have one of these that was made in the USSR, found it at a thrift store
Excellent previous modification. Enjoyable present consideration. I do hope that you will continue to try to improve it and take us along with you.
Many thanks!
I do wonder what the voltage curve looks like on that AC generator. White LED need about 1.7 volts
to turn on? If the volts generated are only, say, 2 or 3 volts peak-to
peak, then most of the energy is wasted. It might be best to have 6 LEDs: two red, two green, and two blue. The reds will turn on at .7 volts, the green at a slightly higher voltage, and then the blue. Also, the voltage when it spins down, then red will but the last to light.
If you replace the magnet with a neodymium magnet about the same size (or even somewhat smaller)would it have more light?
I'm sure it would, but it would also be harder to pump. No free lunch!
@@tsbrownie would it be easier to spin without the coil?
@@franzliszt3195 Yes, but there would be no electricity.
@@tsbrownie I know that 🙀
You say it will coast a lot longer. Is that due to back EMF, or did you mean it will light a lot longer?
The flywheel will spin longer because the load is smaller (but the light output is brighter because the LEDs are more efficient).
I got a yellow colored version somewhere with a burned out bulb.
It's at least 20 years old. I couldn't find a bulb to work in it so it got put aside.
I wonder if a bridge rectifier and a dc to dc buck converter board to stabilize the voltage might make it run at a slower pumping speed?
I can't guess the tradeoff between power lost in the circuits verses just going straight to the LEDs. Give it a try and let us know.
@@tsbrownie I've got all the parts and I will definitely try it the next time I run across my flashlight.
I wonder of a capacitor (flat type) and a joule thief would work for this...
I thought about a cap, but not a joule thief.
I have some of these, I have thought about converting them to use an LED.
I'm wondering, what if you were to out a cap in there and a switching buck-boost converter?
That should basically make it rechargable by hand, no?
And another question: ain't you afraid that the current will get too high for those tiny LEDs?
I've looked into adding rectifiers and caps, but I'm not convinced the losses are worth it. There are some ready-made ones that can be charged up, but I've found they are not efficient, and it takes a long time to get any charge stored up. The current coming out of the generator is tiny, it's the voltage that spikes. But if you look to see how they make LEDs extra bright, they pulse them on and off. The pulse on exceeds the LED's constant power rating, but turning it off allows it to cool. The LEDs are only on half the time, and they **might** exceed the voltage for only a fraction of the wave.