I hate when people say this because there are a hell of of lot of books that are total garbage.
Correction, Watching garbage on YouTube is unhealthy for your brain.

Correction of my own - yes, you're right. Garbage on YouTube IS unhealthy. But I still stand by my final comment, books are your best option.

I guess the trick with YouTube is to spot the BS from the Better Science. I HAVE learned things from YT. But I've seen a lot of crap as well. Word of warning - be careful what you click on. YT will flood you with the same sort of stuff. I made the mistake of clicking on a pretty girl. Now my wife wants to know why my YT is full of - - - never mind.

 

Correction of my own - yes, you're right. Garbage on YouTube IS unhealthy. But I still stand by my final comment, books are your best option.

I guess the trick with YouTube is to spot the BS from the Better Science. I HAVE learned things from YT. But I've seen a lot of crap as well. Word of warning - be careful what you click on. YT will flood you with the same sort of stuff. I made the mistake of clicking on a pretty girl. Now my wife wants to know why my YT is full of - - - never mind.

Yes, good books are the best option for serious study IMO too but I'm a boomer, from an era where books, magazines, etc.. were the only option to see if you had an interest in a new subject.

 

A book used as a text at respectable schools is likely to a bit more accurate than the typical u-tube video.

 

A book used as a text at respectable schools is likely to a bit more accurate than the typical u-tube video.

Respectable is a value judgement. The good Dr's physics video's on youtube will always respectable.

 

But in theory, if I have 4 small solar cells and combine this with let's say 12 piezo disks I should be able to at least charge an AA battery?

Someone left the comments under the video below:
I’m making the same project but my piezos didn’t produce more than 0.1 volt.

So, how many pieces of piezo that you have to prepare for the rechargeable batteries?

If you need over 30 even 40 pieces of piezo, are they suitable for your shoes?

 

A piezo that is hit with a hammer (not simply walked on) produces short duration 2V pulses with very low current.
Then the average loaded voltage is almost 0V.
The output power of a few small piezo discs that are walked on is very low, but battery charging needs plenty of input power.

 

About ten years ago there was an article in Design News about an experiment to generate power from folks walking on a sidewalk, disturbing piezo elements some how. The concept was that traffic would produce enough enery tp charge capacitors and power lighting after dark. I commented that if walking on that walk were able to deliver useful energy, it would also add enough effort so that folks would walk elsewhere. Evidently that creator realized that the correct numbers verified that concept and the project changed to something else.For a useful amount of energy to be produced by walking, the effort will also be a useful amount, much more than folks would be happy with delivering.
Consider the physical effort to generate one little spark using a press-button spark igniter device. Not a huge effort, but it would soon get old if added to every step you took.

 

In the realm of generating electricity, someone took an Olympic Cyclist, one trained for sustained output, able to pedal like crazy. They then built a stationary bicycle with a generator attached. They hooked the generator to a 700 watt toaster. The experiment was to see whether he could produce enough power to toast a slice of bread. Keep in mind this is a trained body builder professional. He barely produced enough energy to toast a slice of bread. Also consider that 700 watts is no small task. But it shows how much energy it takes to create energy. And no, I didn't mis-quote myself. I asked how much energy does it take to create energy? The proof is in the putting. You can not "Create" energy. You can only transform it from one form to another. In this case "Human Energy" is converted into "Electrical Energy". But the fact remains, it takes energy to make energy. Not "Create" it, to make it. Or to transform it.

Olympic Cyclist vs Toaster; Can he power it?

So your concept of using piezo shoes to charge a battery, um, you're going to be walking a whole lot just to charge a double A battery. Likely your medical bills from all that pounding on your joints will cost a whole lot more than what it would cost to buy AA batteries or to buy a Charger and Rechargeable AA batteries.

 

Even if you consider the 700 watt toaster is for toasting two slices of bread, if you were to isolate power to only one side of the toaster that's still 350 watts. Note the size of this guy's legs. Even at 350 watts, it's going to be a job. I don't think the amount of energy he's going to get from eating that slice of toast is going to be anywhere close to the energy he expended to toast it. In the end, the cyclist is toast; laying on the floor recovering from the brief exercise.

Your shoe battery charger? If you haven't figured out by now it's not a feasible approach then I haven't another comment for you. Good luck with whatever you decide.

 

About ten years ago there was an article in Design News about an experiment to generate power from folks walking on a sidewalk, disturbing piezo elements some how. The concept was that traffic would produce enough enery tp charge capacitors and power lighting after dark. I commented that if walking on that walk were able to deliver useful energy, it would also add enough effort so that folks would walk elsewhere. Evidently that creator realized that the correct numbers verified that concept and the project changed to something else.For a useful amount of energy to be produced by walking, the effort will also be a useful amount, much more than folks would be happy with delivering.
Consider the physical effort to generate one little spark using a press-button spark igniter device. Not a huge effort, but it would soon get old if added to every step you took.

Similarly, harvesting energy from vehicular traffic on a road just results in worse fuel consumption in the vehicles passing over the road. Considering how efficient such a scheme might be, it would be cheaper to pay for street lighting through general taxation.

 

The AA battery he wants to charge produces 1.4V at about 500mA= 0.7W for about 4.6 hours.
Then if it does not explode the battery can charge with 700W by the athlete for 18 seconds, or it can charge all day by a small solar panel, or it can charge for weeks by hundreds of piezo discs in many shoes.

 

The AA battery he wants to charge produces 1.4V at about 500mA= 0.7W for about 4.6 hours.
Then if it does not explode the battery can charge with 700W by the athlete for 18 seconds, or it can charge all day by a small solar panel, or it can charge for weeks by hundreds of piezo discs in many shoes.

All very true. The point of the toaster video is to show how much effort it takes to produce something useable. Granted, there's a world of difference between 700W and 700mW (Watts versus MilliWatts). The point is that harvesting energy from a shoe, even if you could produce the amount of energy needed would take several world class athletes running several triathalons every day just for a single AA battery to be charged. By the way - those numbers are purely fiction. Intended to make a point rather than to be any kind of scientific evidence. Still, the point is that the shoe battery charger is impractical. To say the very least.

 

An AA Ni-MH battery can also be charged for weeks with a low voltage fan used as a generator on his hat.

 

A PM DC brushed motor driven from a roller against the wheel of roller blades could possibly produce useful amounts of power. But it would add some drag, and that might make things challenging. But that could charge a battery for the TS. But are roller blades allowede on the sidewalk where the TS resides?? Do we even know??

 

 

You may have better luck charging your battery with a microphone.

 

You may have better luck charging your battery with a microphone.

I did see that demonstrated many years ago. Of course for the microphone they used several bass loudspeakers in large enclosures, And for the sound source they used the roar of the ocean waves nearby. And for the load they used a flashlight bulb. So certainly there IS a "free lunch", but it is rather expensive.