Wind Turbine PMA for Backup Human Powered Bicycle Generator. Looking for advice on volts, cooling, manufacture, charge controller, ect.

[Hogheavenfarm]

There is a lot of information on this if you google "F&P wind turbine". Some people run two of these on the same shaft for more power. They are very heavy though, about 30 pounds for just the turbine part. The shaft is a key component, so retain that and the plastic hubs that slide on it. I have access to a waterjet so I was able to cut additional hubs to match the shaft myself. Balancing the assembly for wind use is always an issue due to the rotor size (13"). This has been my issue and I am redesigning the mounting base to clear the rotor diameter but keep it closer to the pivot center, then a longer tail to counterbalance it. Most PMA's I have looked at, in the affordable (cheap) range are just modified car alternators. The advantage they have is a small overall diameter (about 7-8") as opposed to the bigger one on the F&P, and they are a little lighter.

 

[KITROBASKIN]

Perhaps inspiration for heavy duty bike pedaling:
A protein that is associated with keeping the brain vital was studied to see what would most stimulate production of it. One option was just 6 minutes of high-intensity vigorous cycling. A very narrow study, however...

Just six minutes of vigorous exercise a day could keep your brain healthy

Just six minutes of intense aerobic exercise a day could be one of the most effective ways to keep you brain healthy into old age. New research has found brief bursts of exercise increase levels of a brain protein known to optimize cognitive health.

newatlas.com

 

[YahwehIsMyEl]

Perhaps inspiration for heavy duty bike pedaling:
A protein that is associated with keeping the brain vital was studied to see what would most stimulate production of it. One option was just 6 minutes of high-intensity vigorous cycling. A very narrow study, however...

Just six minutes of vigorous exercise a day could keep your brain healthy

Just six minutes of intense aerobic exercise a day could be one of the most effective ways to keep you brain healthy into old age. New research has found brief bursts of exercise increase levels of a brain protein known to optimize cognitive health.

newatlas.com

Very interesting! Funny the way people who use their bodies seem to keep them longer.

 

[YahwehIsMyEl]

All you need is a diode good for the amount of current you’ll be generating and some overcurrent protection-a fuse or breaker. That will keep your motor from draining your battery.
Yes, you will only make power when you spin your generator fast enough to get the voltage higher than the battery voltage.
Also yes, it will be very hard to get your motor up to 14.5 volts (if you have reasonable losses) because you’d have to fully charge your battery to get there. If I apply a voltage that puts 9,000 watts into my 48v battery the battery voltage goes up .01 volt every minute or so. I don’t know how big your battery is. But it will take a lot of sweat to put much power in.
As you attempt to pedal faster, the current produced by your generator wi shoot up, and the force required to turn the pedals wi shoot up. At 12 volts by the time you’re putting 100 watts into the battery it’s still only 8 amps. The cable you need isn’t that big.

Alright so I have been doing a lot of thinking. I am hoping you can help me figure something out.

My goal is this:

I want to basically be able to stand on the pedal of my bicycle, and have it move down slowly, more powered by my weight and gravity then my actual pedaling power.

I weigh about 150 pounds. From my understanding, that means when I am standing on my pedal there will be 150 pounds torque on my bike chain, and then running through my system.

I have decided to go with dc motors, but what I don't understand now is how to figure out find out how many watts the motor will produce when I put my 150 pounds of torque on the shaft and how much resistance I will have when hooking it up to a 12 vt battery.

Here is what I have come up with so far:
150lbs = 68 kg/s (I think)
68 kg/s is about 1 HP.

So does this mean that if I get a 12vt permanent magnet motor that is 1 hp, and I apply my 150 lbs to the shaft through the pedals, it will produce 12 vlts?

If so, can I also gear it so that I can rest on each pedal for 3 seconds while my weight pulls the pedal down?

This would give me a cadence of 10 rpm, but if I gear that 1/200 that would give me 2000 rpm at the motor. The motor linked below is a good example of what I am looking at.

VEVOR DC MOTOR 1HP 56C Frame 12V/1750RPM TEFC Permanent Magnet 882510650407 | eBay

VEVOR DC Motor 1/2HP 56C 90V 1750RPM TENV High Torque Permanent Magnet Motor. 1HP 12V 56C 1750RPMPermanent MagnetDC Motor. Base RPM 1750RPM 1750RPM 1750RPM 1750RPM 1750RPM. ã MULTIPLE APPLICATION ã - DC motors have a wide range of applications.

www.ebay.com

Basically my question is, would the resistance of the 12 vt battery hooked up to this 1 hp motor be enough to keep it from going faster than 10 rpm at the pedals if I gear it 1/200, or would my full weight cause it to spin faster. And/or, would this be too much resistance? I.e, am I underestimating the resistance of the battery so that even me resting my full weight on the pedal at this gearing would not be enough to turn it fast enough. to generate 12 vlts?

Also, about how many amps would I produce with this setup? I am applying 150 pounds to the shaft and the motor is spinning about 1700 - 2000 rpm. About how many amps will that give me?

I feel like I am missing something in all this, but right now my hope is this:

Get that 12 vt 1 hp motor
Hook it up to my system with a gearing of 1/200
Be able to rest my full weight on each pedal and there will be enough resistance that I will be able to rest on each pedal for aprox 3 seconds while my weight drags the pedal down.
Have it producing 12 - 13 volts at least 7 amps.

 

[DougfromdaUP]

Whew! That’s a lot of figuring.
There are a couple of errors that you have made.
One horsepower is 550 foot pounds per second, not 150. So you’re off by a factor of 3.7.
I’m not sure why you want to pedal at such a slow speed. Three seconds per half revolution is 10 rpm. I’ve never seen a bike racer do that. I’m old, yet my most comfortable pedaling speed is 70 rpm or so.
The torque on the crank, and the pull on your chain, is going to depend on the length of the crank arm. If that was one foot long, you would put 150 ft lbs torque on the chain at two points as you pedaled— the two times your feet are level. If you’re just letting your weight pull the pedals around, there’s zero torque when the crank is straight up and down. You don’t notice this when you’re pedaling a bike so much, but the rpms of your generator will vary greatly as your feet circle the crank. I added weight to the rim of the wheel(20 pounds) to smooth this out.
That one horsepower motor would work, but it’s about ten times the motor you need.

 

[YahwehIsMyEl]

One horsepower is 550 foot pounds per second, not 150. So you’re off by a factor of 3.7.

I see, that makes more sense!

I am hoping to pedal so slow because I'm actually considering standing on the pedals rather than sitting at all, and if there is too little resistance I will be fighting against myself, trying to apply pressure to the back pedal to keep myself from going forward too quickly. If there is resistance like I believe there will be, I will rest my full weight on the pedal and it will gracefully be pulled down by my weight.

I am also planning on using flywheels to smooth out the motion though.

As far as that motor, that is actually one of the cheaper options I can seem to find. With that size though, will I run into issues even being able to turn it at all though? From what I understand so far though, I'll be able to get it up to 12vt speed, I just probably won't be able to turn it past 5 amps or so.

I have also seen this on there, however I don't like that I can't find any specification about it, like rated speed and such.

FreeEnergy 12V/24V DC Permanent Magnet Motor PMA for Wind Turbine Generator 350W | eBay

FreeEnergy 12V/24V DC 350W. for DIY Wind Turbine /Hydroelectric / Fitness Bike. 6 x 62" Wind Turbine Generator Blades + Hub + Nose Cone 6 socket fit Air-X 403. TowerUp Wind Turbine Generator Tower Base Stand Mount Foundation Easy Up & Down.

www.ebay.com

I am still considering a treadmill motor, I just feel like as those motors are rated at 120 - 220 volts I would be better off just getting something rated at 12 vlts already. But would the treadmill motor really work well? If so, what size do you recommend?

 

[Frick]

As an interesting note, Lance armstrong was able to produce about 100 watts max on a continuous basis. They tracked it as part of his training, tech people, bicycle people, doctors, nutritionists, special energy bars…. The Works.
I live in a rainforest, some days we can’t see the sun or mountains or trees even. My 4kw solar array sometimes says 150 watts at midday. But hey! That’s still 150 watts! If we get even an hour of sun we recharge enough, 3 hours and the batteries are topped.

 

[YahwehIsMyEl]

As an interesting note, Lance armstrong was able to produce about 100 watts max on a continuous basis. They tracked it as part of his training, tech people, bicycle people, doctors, nutritionists, special energy bars…. The Works.
I live in a rainforest, some days we can’t see the sun or mountains or trees even. My 4kw solar array sometimes says 150 watts at midday. But hey! That’s still 150 watts! If we get even an hour of sun we recharge enough, 3 hours and the batteries are topped.

Very interesting. I know it is not the most practical thing, however it is more for nightime that I am concerned about at the moment, and I am really just interested to see it work. I still want to make it as efficient as possible though! I would be interested in what kind of setup they used for Mr. Armstrong, as I am sure they put a lot of research into it, and they have the resources to do that!

 

[YahwehIsMyEl]

Whew! That’s a lot of figuring.
There are a couple of errors that you have made.
One horsepower is 550 foot pounds per second, not 150. So you’re off by a factor of 3.7.
I’m not sure why you want to pedal at such a slow speed. Three seconds per half revolution is 10 rpm. I’ve never seen a bike racer do that. I’m old, yet my most comfortable pedaling speed is 70 rpm or so.
The torque on the crank, and the pull on your chain, is going to depend on the length of the crank arm. If that was one foot long, you would put 150 ft lbs torque on the chain at two points as you pedaled— the two times your feet are level. If you’re just letting your weight pull the pedals around, there’s zero torque when the crank is straight up and down. You don’t notice this when you’re pedaling a bike so much, but the rpms of your generator will vary greatly as your feet circle the crank. I added weight to the rim of the wheel(20 pounds) to smooth this out.
That one horsepower motor would work, but it’s about ten times the motor you need.

Hey there!
I actually have my generator set up now! I went with This Motor and it works great! I'm a little out of shape from the winter, but as of right now I'm able to produce about 60watts for two hours at a time. This works perfectly for me. At some point I think I'll post some pictures here to show what I came up with.

However I am having an issue. I sometimes get an overload(I think) that usually discharges some sort of shock...

Here is what I am working with:

I have my motor hooked up to my battery with only a blocking diode as was recommended, though right now the battery is only a single 12vt tractor battery that I am using for testing purposes. I have a 300 watt pure sine wave inverter hooked up to the battery as well, and am running my laptop off of that.

I get my battery up to 13.2 pretty quickly when producing 60 watts. This battery usually stays at about 12.5 when not charging and at no load. At about this time, every now and then, maybe every 15 or 20 mins, I will get a static discharge from the outside of my laptop (connected to the system via the inverter) that will shock me, though one time there was a shock in my battery volt meter that shorted it out, and I needed to reset it before it would display again.

My theory right now is that I am producing too much electricity for my battery at once. I believe this to be the case because my laptop only draws about 30 watts, and as I am putting 60 watts in and my battery is already fully charged. Also, If I only produce 40 watts, only enough to just put a little charge in and keep my laptop plugged in, I don't get too much of an issue. However once I try producing over about 55 watts, it starts discharging every now and then. And if I try going up to 70 or 80 watts, the discharges become much more frequent. Again, I am only going through the blocking diode, instead of a charge controller.

This is why I had originally thought I would need a charge controller so that I would not overload something, as when the battery is a different states in the charge in can only handle different amounts of charge, at different volts and amps, and I don't think I can control it that well with my pedaling only. If I go through a charge controller it will only let the amount through that my battery can take. Considering my wattage is varying bassed on the speed and effort that I pedal, when I am producing 60/70 watts, my voltage I am producing is about 13.8/9. And at 40 watts it is about 13.3/4, and my amps also vary between about 3 / 4, I feel a charge controller would be able to take that, and regulate it into a voltage and amperage that my battery can handle, and stop any overloading from happening.

So, I am here to ask if I am missing something. I know all my wiring is correct, the positives are not connected to the grounds in any way...
I feel like I should at this point just add in at least a small solar charge controller like This one into the system.

Or am I missing something else obvious? But overloading my battery, in other words bringing it to a voltage it can't handle that quickly, seems to be the only thing I can think of that would cause a shock like that.

Any advice is appreciated.

 

[YahwehIsMyEl]

How fast you pedal controls the generator voltage.
How HARD it is to pedal decides the current.
Below some pedal speed it will be really easy to turn, requiring almost no effort at all. There will be no charging current either.

Any thoughts you might have on my current problem would be appreciated.

 

[Hogheavenfarm]

The generator you referenced is 24 volts. You are using this to charge a 12 volt battery?

 

[YahwehIsMyEl]

The generator you referenced is 24 volts. You are using this to charge a 12 volt battery?

I have it geared so that I am only spinning at half rpm to generate 12vt.

 

[Hogheavenfarm]

Deep cycle FLA or is it a standard cranking battery? typically you would float a 12v battery at 13.6v, and charge at something higher, like 14.5 to 14.8 for at least 2 hours for absorption. Doesnt sound like this will fully charge a battery. Do you have a 12v charger? ie fully charge the battery, then take your measurements. As for the shock thing, no idea on that, doesn't sound right, Wimshurst effect?

 

[YahwehIsMyEl]

Deep cycle FLA or is it a standard cranking battery? typically you would float a 12v battery at 13.6v, and charge at something higher, like 14.5 to 14.8 for at least 2 hours for absorption. Doesnt sound like this will fully charge a battery. Do you have a 12v charger? ie fully charge the battery, then take your measurements. As for the shock thing, no idea on that, doesn't sound right, Wimshurst effect?

It is just a standard cranking battery, lead acid, though it is fairly old and pretty heavily used. It had been charged with a charger before I took my measurements, and even after the charger brought it up to "full" after it was disconnected it would bleed down to about 12.5

As for the shock, I tried just pedaling slower last night, at is was going fine until I went to touch my bike with one hand while the other was still on the laptop, at which point it shocked me, the shock going from my laptop to the bike through me. Or possibly the other way around, I'm really not sure. It does seem like there could be some sort of Wimshurst effect going on. Maybe I need to ground something to prevent a charge from building on the bike frame or something? I'm kind of at a loss, I was not expecting this kind of issue.

 

[DougfromdaUP]

It sounds like your battery should be recycled today. If it won't even hold voltage when you remove the charge it is toast.

Is the shock just a quick static discharge? If so, just bond everything with small wire or some thing moderately conductive.

 

[YahwehIsMyEl]

It sounds like your battery should be recycled today. If it won't even hold voltage when you remove the charge it is toast.

Is the shock just a quick static discharge? If so, just bond everything with small wire or some thing moderately conductive.

Yes, it's unfortunate not the best battery. However it does still hold enough of a charge to run small things like my laptop for a little while, it just does not run at the best efficiency.

And yes, the discharge is just a small static discharge.

When you say bond everything though, what exactly should I bond?

The Bike Frame, my Laptop?
The Bike Frame, laptop, and myself?
The Bike Frame, laptop, battery?

And should whatever I connect in this way be also grounded to the actual ground? Or is just running to the negative of the battery enough, as they do in cars and boats? Or do they just have to be connected together so that static does not discharge between them?

 

[DougfromdaUP]

Just connect together whatever has a potential difference to keep static from building up, start with laptop and bike. You probably get to bike potential when you're pedaling,

edited for clarity