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@cranky • 11 Jun, 2009
I guess this is my first proper post.Really glad i found this forum:smile::smile:.

Idea for society(which i don't know if feasible😒):I was just thinking.We see many tailors working at almost every corner of the street during late evenings under tubelights or lamps.Now, if we can generate some amount of energy from the spinning wheel of the sewing machine,I thought we can save energy.By attaching a cyclo dynamo to the wheels we can convert the mechanical to electrical energy(though this may be only a few volts or even lesser).Further,if we place a piezo electric material below the peddle(or whatever you call that-part of the sewing machine near your foot)we can further generate(or convert to be precise)energy.
😕😕
@Saandeep Sreerambatla • 11 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

Really this is an awesome idea.

So have any idea to implement it practically , have you thought of the equipment required etc etc..
really its an fantastic idea 😀
@cranky • 11 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

ah..thanks(truth or not..you made me feel good😀)...i don't know how a cyclo dynamo works(tried wiki but didn't get much info-got to understand that it is similar to bicycle lights thats it😔)...can you please help me proceed
@cranky • 11 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

somebody please..😔
@cranky • 15 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

i would be very glad if CEans can help me out😁in any way possible
@Kaustubh Katdare • 15 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

cranky
I guess this is my first proper post.Really glad i found this forum:smile::smile:.

Idea for society(which i don't know if feasible😒):I was just thinking.We see many tailors working at almost every corner of the street during late evenings under tubelights or lamps.Now, if we can generate some amount of energy from the spinning wheel of the sewing machine,I thought we can save energy.By attaching a cyclo dynamo to the wheels we can convert the mechanical to electrical energy(though this may be only a few volts or even lesser).Further,if we place a piezo electric material below the peddle(or whatever you call that-part of the sewing machine near your foot)we can further generate(or convert to be precise)energy.
😕😕
A similar idea was discussed earlier. We had brainstormed on using GYM equipments to power the GYM. 😉

The idea is good. How do you go about implementing this?

I see lot of sewing machines are electric powered. I don't think it's too difficult to setup mechanism to convert the mechanical power from sewing machines into electricity. However, there will be many challenges in implementing the concept.
@Ashraf HZ • 15 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

I've got a hand powered LED torch light that I got as a gift from a Cisco seminar. One has to keep "pumping" it to generate the electricity via a mini dynamo.

Though, its not wise (nor sense) to attach something like this to something already powered by electricity. You might as well divert some of its power to lighting directly 😛 Something like this would work for those full manual sewing machines with those big flywheel.
@cranky • 16 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

@big_k,ash:thank you😁for replying
@ash:what i meant was manual sewing machines only.not many street side tailors use electric powered ones😒 i read about lighting bicycles with cyclo dynamos.so i was thinking if similar thing is possible😀
@big_k:can you please elaborate on that?
@Ashraf HZ • 16 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

Sorry cranky, I was responding to Biggie's comment about electrical sewing machines, haha. I forget to quote at times.

Did not mean to dampen your idea 😉

If we add some lead acid batteries, the tailors can start charging from the day.. so the accumulative power from the battery and the night's work can hopefully be enough to power the lights 😀
@cranky • 16 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

@ash:he he😀..thanks again..yes bingo...now how should i charge😒sorry...i have no clue..
@Ashraf HZ • 16 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

Lets start from the basics and work our way up. We know that changing the magnet field around a conductor will induce current, so the prime choice would be to use something that is moving continuously mechanically.

We'll try something simple. Most bike dynamos are not dynamos as such.. they are alternators that generate AC rather than DC. This is because its a simpler set up.. and its easier to convert AC to DC rather than the other way round.

So, the set up would be strong magnets (preferable neodymium from HDDs) fixed on the thing that is rotating.. such as the sewing machine's flywheel. Then, a stator (coils wrapped around a core) is placed around this ring but is not attached to the flywheel. And thats about it for generating AC.

To charge the batteries, we'll need to rectify and smooth it out into DC using caps and diodes.

cranky, lets think up of a hypothetical situation to apply this.. as in, how many sewing machines will be used, how long will the light need to be operated for, etc. Once we get some guidelines, we can roughly gauge how much power is needed.
@cranky • 18 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

@ash:awesome!😁
i was wondering if a cyclo dynamo could be used in spinning wheel like this
The Circuit of the Dynamo Lamp

Lets say the tailor works from 10 to 6 with a hour's gap for lunch and another hour for otherwise- so total of 6 to 7(max) hours after which he may require light(if the tailor is from malaysia,he may require light even before 6,considering the fact that the sun sets earlier there 😁).so how much power at the max ca we generate.(plus in case we are interested in generating further energy from piezo?)
@Ashraf HZ • 22 Jun, 2009 Re: Idea to generate minimum energy-don't know how to proceed

Great work Cranky!

From your PM, you mentioned that you've inquired a tailor, who said he works an average of 10 hours. Is it on the sewing machine or just in general?

The next step is to find the nominal RPM of the flywheel (or any rotating thing) of the sewing machine. There are specs online of the electrical variant, but the manual one is still hard to find. If anyone could help find it, it'll be helpful 😀

After knowing the RPM, we could pick some alternators on the market that we could use and roughly estimate their power output.
@cranky • 23 Jun, 2009 @ash:thanks😁

Can you suggest any means by which i can find an average rpm.now that i took a video of the flywheel (when on action)when i enquired the tailor...will that help😕
@Ashraf HZ • 23 Jun, 2009 I'm not sure if it'll help, since the RPMs would be a lot faster than the camera frame rates, but we'll analyze it and see anyway 😀 Can you upload it to rapidshare?
@cranky • 26 Jun, 2009
ash
I'm not sure if it'll help, since the RPMs would be a lot faster than the camera frame rates, but we'll analyze it and see anyway 😀 Can you upload it to rapidshare?
Sorry for the late reply..i don't have a card reader to upload video from digi camera..can you suggest as to how else to upload the video😕😕
@Ashraf HZ • 26 Jun, 2009 Do you have a USB cable that can connect the camera to the PC by any chance? IF not, maybe you can borrow a friend's laptop. They might have a card reader.

[EDIT]

Found an obscure online manual which might reference to the manual machines, but I'm not too sure. They say the max speed for these are 600 RPM. I assume that is the speed of the flywheel attached to the machine.. so its possible we could use that value regardless if that Singer model was foot powered or motor.

Also, this link might be useful for us. An engineer who plans to use the foot pedal for grain milling (i think):
https://www.thefreshloaf.com/node/12173/treadle-milling

If you scroll down to the comments, one guy mentioned being able to pedal at 100 rpm. cranky, can you take some quick measurements of the sewing machine at the shop? The diameter of the drive wheel at the pedal, and the diameter of the flywheel at the machine itself (the silver one).
@cranky • 28 Jun, 2009 😁😁

sure..will take measurements and tell you!
"The diameter of the drive wheel at the pedal"-hey but it is in rectangular shape right

flywheel...will let you know
@Ashraf HZ • 28 Jun, 2009 Here's a manual sewing machine. Is this the like the one used by the tailor?

[​IMG]

1. Flywheel with machine pulley. we'll try attaching the alternator here.. but with a one way ratchet, since we want to still allow the tailor to turn the flywheel backwards by hand easily when adjusting the needle bar.
2. I'm not sure what it's officially called, but its still a sort of drive wheel, haha.
@raj87verma88 • 28 Jun, 2009 Interesting thread and equally interesting discussions. I will interrupt neither Ash or Cranky. Just a spectator if you don't mind.
@cranky • 28 Jun, 2009 [​IMG]


This is one of the pics..
By the way we can attach the dynamo to the driver wheel(as you named it😉)?

Moreover,can we attach any piezomaterial bellow the paddle?..that could be advancements to the project...he he😁

@raj(...): please join in too
@Ashraf HZ • 28 Jun, 2009 Nope, its better to place it on the flywheel. High RPMs are essential for proper electric generation, since you'll want the coils to cut the magnetic field lines as frequently as possible.

Yes, you can attach a piezo material below.. however, keep in mind that the pedals never touch the ground while it's "see-sawing". Adding some sort of obstruction will dampen it and reduce the work to the drive wheel. Its better to place the piezo material under something not directly related to the operation of the sewing machine. Like a mat thats frequently walked over.

[EDIT]
patty, do share any ideas that you have 😀
@cranky • 28 Jun, 2009 hmmm..i failed to think that way...is it possible to place two dynamos then?..and then store energy?

after this how/where do you think we should place the rest of components
@cranky • 29 Jun, 2009 HEY😁😁
i got he measurements for the wheels
sorrry but these are approx value only
Diameter of flywheel= 5'' or 13 cm
Diameter of driver wheel=18'' or 46 com (nearly)
@Ashraf HZ • 29 Jun, 2009 Good work!

So, if we assume a nominal max RPM of the drive wheel to be 100 rpm, then the flywheel's max RPM is ((100 x 18)/5) = 360.. well within the machine's tolerances.

However, is that enough speed for alternator shaft? Or do we need to add more gears? We might need to create a test rig to verify this.

Lets see from the perspective of the output requirements. How much power do we need to power a standard CFL light bulb as well as an LED light bulb?
@lal • 30 Jun, 2009 My opinion on the piezo: Why not place them below the legs of the machine? 😕 Not below the pedal! So there wont be any obstruction to tailors work and yet we can extract energy...😀
@cranky • 30 Jun, 2009 Typical indicator LEDs are designed to operate with no more than 30–60 milliwatts [mW] of electrical power. Around 1999, Philips Lumileds introduced power LEDs capable of continuous use at one watt [W].
see link

@lal:but where are we varying the stress to allow piezo to work😕
@kashish0711 • 30 Jun, 2009 Great idea + great discussion

but you guys in between forgot that for whom you are building this stuff. :\

If you add an alternator to the machine, it is gonna make it more harder to move the machine handle and gonna decrease his efficiency.

Secondaly the speed of the sewing machine won't matter, it will run as fast as a man can make it run.

The elctricity produced won't be constant and the bulb will keep flickering and that will create irritation + will weaken his vision slowly.

Use of peixoelectric is good idea and there is no need to put it in paddle etc. coz you don't need to deform it to any great extent to produce the voltage required. In fact the vibrations produced by the sewing machine should be enough to deform the piezo electric crystals and should produce voltage which can be stepped up by a small transformer and used to light a bulb.

For me the best possible thing for him can be buying a baterry and a charger that should do it.
He can use the baterry in night and charge it during day.

The things you guys are discussing can be done efficiently but there will be a problem with their use with a tailor.

I can provide with technical details if needed on the alternator thing but for me that thing is not needed in this case.
@Ashraf HZ • 30 Jun, 2009 Good points being raised 😀

But we didnt forget.. 😛 A few posts back, we did discuss about charging a battery during the day. During the night, it will be the battery that powers the lights.. similar to light powered by P.V cells. So, we are trying to see if the total power output during the day can power the lights up during the night. Output of alternator will be A.C, so we'll have to rectify and smooth it out with diodes and caps to charge the batteries properly.

Efficiency wont be hurt that bad. As long as we design/use a low drag alternator, the tailor can still do his work. He would still need to work a bit harder since we are using human power to generate electricity after all.. but with appropriate gearing, it should be fine. I've tested some hand held alternators and used manual sewing machines before (when my mom still had it), they aren't that difficult to turn. The key will be the flywheel attached to the sewing machine.

At the moment, using the sewing machine as a mill is the most viable way to get off grid electricity.
@lal • 01 Jul, 2009
cranky
@lal:but where are we varying the stress to allow piezo to work😕
Arent we discussing about manual sweing machines?
Then i think each time the tailor push on paddle, a fraction of force is ofcource tranasferred to the ground by the machines legs. And this will be always variying with his each push. So cant we use a piezo there?😛

Correct me if my views are wrong...
@Rohan_sK • 01 Jul, 2009 @ CRANKY : Great idea And Impressive efforts put in by you. You'll surely succeed in your project.
Keep it up and All the Best!!
@kashish0711 • 01 Jul, 2009 well yeah hand held generators might be used but again you don't want the power to go off when he stops.
and if battery is used then there should be no problem as he is not gonna work the whole night, if he does, then he should be stopped and asked to used day light for working
if he is putting only a few extra hours then there should be no problem with the use of battery. 😀
@Ashraf HZ • 01 Jul, 2009 Yep, we'll only see it's feasibility once we worked out the power requirements.

Cranky, what kind of lighting does he use presently? Like, the type of lights and power rating. That way we can see the equivalent luminous flux and see how CFLs and LED light stacks up. Refer to my post here:
https://www.crazyengineers.com/forum...-ce-project-earth-initiative-5.html#post70681

We know pretty much what is required at the moment.
- Transducers (alternator, piezo, etc)
- Regulator
- Charging circuit
- Battery
- Lighting circuit
- Light

From the power requirements, we can approximate the battery capacity. Then from the other side of the coin, we'll see how much work is needed to charge the battery during the day.
@kashish0711 • 01 Jul, 2009 me too waiting for Cranky's reply
and I guess LED's can't be used because of cost. :\
@cranky • 01 Jul, 2009 Sorry for the late reply guys😒
kashish0711
Great idea + great discussion

but you guys in between forgot that for whom you are building this stuff. :\

If you add an alternator to the machine, it is gonna make it more harder to move the machine handle and gonna decrease his efficiency.

Secondaly the speed of the sewing machine won't matter, it will run as fast as a man can make it run.

The elctricity produced won't be constant and the bulb will keep flickering and that will create irritation + will weaken his vision slowly.

Use of peixoelectric is good idea and there is no need to put it in paddle etc. coz you don't need to deform it to any great extent to produce the voltage required. In fact the vibrations produced by the sewing machine should be enough to deform the piezo electric crystals and should produce voltage which can be stepped up by a small transformer and used to light a bulb.

For me the best possible thing for him can be buying a baterry and a charger that should do it.
He can use the baterry in night and charge it during day.

The things you guys are discussing can be done efficiently but there will be a problem with their use with a tailor.

I can provide with technical details if needed on the alternator thing but for me that thing is not needed in this case.
yeah...like ash said,we will be storing energy and utilising it only in the night(or maybe fan-ash note this 😀)

ash
Good points being raised 😀

But we didnt forget.. 😛 A few posts back, we did discuss about charging a battery during the day. During the night, it will be the battery that powers the lights.. similar to light powered by P.V cells. So, we are trying to see if the total power output during the day can power the lights up during the night. Output of alternator will be A.C, so we'll have to rectify and smooth it out with diodes and caps to charge the batteries properly.

Efficiency wont be hurt that bad. As long as we design/use a low drag alternator, the tailor can still do his work. He would still need to work a bit harder since we are using human power to generate electricity after all.. but with appropriate gearing, it should be fine. I've tested some hand held alternators and used manual sewing machines before (when my mom still had it), they aren't that difficult to turn. The key will be the flywheel attached to the sewing machine.

At the moment, using the sewing machine as a mill is the most viable way to get off grid electricity.
thanks to your mom😁😁

lal
Arent we discussing about manual sweing machines?
Then i think each time the tailor push on paddle, a fraction of force is ofcource tranasferred to the ground by the machines legs. And this will be always variying with his each push. So cant we use a piezo there?😛

Correct me if my views are wrong...
hmmm...maybe but not sure...
Rohan_sK
@ CRANKY : Great idea And Impressive efforts put in by you. You'll surely succeed in your project.
Keep it up and All the Best!!
Thanks a ton..looking forward to your comments too
ash
Yep, we'll only see it's feasibility once we worked out the power requirements.

Cranky, what kind of lighting does he use presently? Like, the type of lights and power rating. That way we can see the equivalent luminous flux and see how CFLs and LED light stacks up. Refer to my post here:
https://www.crazyengineers.com/forum...-ce-project-earth-initiative-5.html#post70681

We know pretty much what is required at the moment.
- Transducers (alternator, piezo, etc)
- Regulator
- Charging circuit
- Battery
- Lighting circuit
- Light

From the power requirements, we can approximate the battery capacity. Then from the other side of the coin, we'll see how much work is needed to charge the battery during the day.
what kind of lighting does he use presently?:right now generally tailors if at all use,useonly tubelights...cfls are more expensive right?

for fan and stuff more power will be required?😒😛

is it possible to derieve power from both wheels-flywheel and driver wheel??
kashish0711
me too waiting for Cranky's reply
and I guess LED's can't be used because of cost. :\
my reply..😲..led in the long run won't be effective😒..like long term investement...led's life is better,isn't it(citation needed)?
@kashish0711 • 02 Jul, 2009
cranky
my reply..😲..led in the long run won't be effective😒..like long term investement...led's life is better,isn't it(citation needed)?
LED's will be successful in long run but the initial cost is high. They are the best for usage as they are very efficient and portable and best that they don't emit and radiations or heat and thus helping the enviornment around sewing machine too.
@cranky • 02 Jul, 2009
kashish0711
LED's will be successful in long run but the initial cost is high. They are the best for usage as they are very efficient and portable and best that they don't emit and radiations or heat and thus helping the enviornment around sewing machine too.
so it won't be a bad idea to use them?😕
@kashish0711 • 02 Jul, 2009
cranky
so it won't be a bad idea to use them?😕
no but their cost is a problem
They are very costly. You will have to use them in groups to produce sufficient light.
@cranky • 03 Jul, 2009 hmmm...probably in the long run,it may be efficient...but for the time being lets concentrate on cfl😁
@Ashraf HZ • 15 Jul, 2009 Sorry for the delay of responses. Cranky, can you please check the existing wattage of the florescent light bulbs the tailor uses (50W, 100W, etc)? Then we'll pick the equivalent CFL that can produce the same apparent brightness.

I'd suggest sticking to getting power from the flywheel first.
@kashish0711 • 15 Jul, 2009 Well. we should not see which light he uses. For his work, he will require lighting to be somewhere around 3500 lumens and taking that the light will be placed very near to the object of work, there shouldn't be any loss in lumens in the way.

So taking about say 60 lumens per watt, a 60 watt CFL should be the best bet. I won't go with fluorecent, because that will require more space, and well looking at what he will be working on, CFL will be the best. Its more costly but would surely be better for him, as it will consume much less power and not drain battery as much as fluorscent.

So, I'll go with a 60 Watt CFL. Spiral shape gives best output so that will be best.
@cranky • 15 Jul, 2009 @ash,kashish:thanks a lot guys.Was waiting for a reply😁😁
ash
Sorry for the delay of responses. Cranky, can you please check the existing wattage of the florescent light bulbs the tailor uses (50W, 100W, etc)? Then we'll pick the equivalent CFL that can produce the same apparent brightness.

I'd suggest sticking to getting power from the flywheel first.
hey i don't think we will have to use what he does.I mean we can take an intelligent guess on that s to how much will require,can't we?😒I still don't mind asking him
kashish0711
Well. we should not see which light he uses. For his work, he will require lighting to be somewhere around 3500 lumens and taking that the light will be placed very near to the object of work, there shouldn't be any loss in lumens in the way.

So taking about say 60 lumens per watt, a 60 watt CFL should be the best bet. I won't go with fluorecent, because that will require more space, and well looking at what he will be working on, CFL will be the best. Its more costly but would surely be better for him, as it will consume much less power and not drain battery as much as fluorscent.

So, I'll go with a 60 Watt CFL. Spiral shape gives best output so that will be best.
Great.Spiral ones look great too😁
@Saandeep Sreerambatla • 15 Jul, 2009 Amazing improvement in the discussion 😀

So my idea is , we can generate power to use it elsewhere !! correct ?
@cranky • 15 Jul, 2009
English-Scared
Amazing improvement in the discussion 😀

So my idea is , we can generate power to use it elsewhere !! correct ?
Join us ES.And about "my ides is.."well, I didn't get you😒
@Saandeep Sreerambatla • 16 Jul, 2009 Ok 😀

Let me clearly state my idea then..

The project under discussion is to generate power from the sewing wheel.
Moreover , you people are trying to utilize the power to provide lighting to the tailor.
So , there was a discussion on types of lights to be used.

Instead, the generated power can be saved to a battery first , then we can think of using it for some devices.
So my idea is first we implement something to store the power , then we think of utlization 😀
@kashish0711 • 16 Jul, 2009 yeah if you see the discussion above, we are gonna charge a battery during day, then use the battery power in night. 😀
@cranky • 16 Jul, 2009
English-Scared
Ok 😀

Let me clearly state my idea then..

The project under discussion is to generate power from the sewing wheel.
Moreover , you people are trying to utilize the power to provide lighting to the tailor.
So , there was a discussion on types of lights to be used.

Instead, the generated power can be saved to a battery first , then we can think of using it for some devices.
So my idea is first we implement something to store the power , then we think of utlization 😀
Yes, ES.That is how we have discussed.If more more than required is generated,then like you said we can use it for other purposes😁
@Saandeep Sreerambatla • 16 Jul, 2009 Actually my point here is if LCD 's are costly let him use the power to charge his mobile atleast in the first phase we can improve efficiency and utilization later.

So first concentrate and complete the power storage procedure, any how power produced and stored can be used later tooo 😀
@cranky • 17 Jul, 2009
English-Scared
Actually my point here is if LCD 's are costly let him use the power to charge his mobile atleast in the first phase we can improve efficiency and utilization later.

So first concentrate and complete the power storage procedure, any how power produced and stored can be used later tooo 😀
Good point.so lets get started with the storage part.Now,where to begin😕😒
@cranky • 22 Jul, 2009 can someone help out.Should we use capacitors?😕
@silenthorde • 22 Jul, 2009
cranky
can someone help out.Should we use capacitors?😕
Great thread Cranky and Ash.

I think we are missing something here. We need to assume an average speed for the flywheel, assuming human limitaions and try to calculate the power that will be generated.

Only then can we think of an application. Maybe a 60w CFL will last for an hour or half. We need to calculate the energy that will be produced in Watt-hour, it will serve two purposes:

1. decide our application.

2. Decide our power storage system.

In any case power storage in a capacitor will be extremely costly because it will be extremely bulky. The best option would be go for for a small rechargeable battery, used in emergency lights.


Regards
@Ashraf HZ • 25 Jul, 2009 Yep, we will recharge a lead acid battery. Probaby 12V. Current capacity will still need to be decided I suppose.

Here's what I fear about these types of discussions. Originally, our application was to provide lighting. But along the way, we may get sidelined with other potential applications. Perhaps it is better to have one target and focus our efforts in that, to be more productive. I mean, our job is to solve an existing problem, not find more problems to solve.

So if not lighting, we have to assume another application.

Is 60W our target? Lets try for a 12 VDC rated one.

LINK

1A max discharge, so it'll be a 12W CFL. Far from the 60W CFL, but is nearly equivalent to a 60W incandescent.. so perhaps sufficiently bright to cover the workspace.

That assumptions will make other things easier. 12V lead acid with a 4000mAH capacity, provides at maximum 4 hours of lighting. Is that sufficient?
@kashish0711 • 25 Jul, 2009
cranky
can someone help out.Should we use capacitors?😕
for what??

ash
Is that sufficient?
Yup, We can't allow him to work day/night, shifts of 07:00 AM to 01:00 PM, 02:00 PM to 06:00PM, then 07:00 PM to 11:00 PM is the maximum time that he should be allowed to work.

07:00 to 11:00 will be the time we use our battery. 😀
@kashish0711 • 01 Aug, 2009 Haha get him this
Brother International - Home Sewing Machine and Embroidery Machine
only 4.5 lakhs lolz
@Adithyavalli • 01 Aug, 2009 16_Channel water level controller

@cranky • 05 Aug, 2009 @silenthorde:thanks.We are presently sticking to lighting😒.
@ash:great!Now i guess that much would be more than sufficient.
but once the energy is stored,it can be used for other applications requiruing same power right
@Ashraf HZ • 05 Aug, 2009 Yeah, it can be used for other applications.

Damn kashish, thats one cool machine 😛
@kashish0711 • 05 Aug, 2009 guys anyone interested in making the circuit. I don't have much experience in designing circuits but will still try. anyone else??

I think we have been discussing it long enough, time to actually work on it now.
@Ashraf HZ • 06 Aug, 2009 I think I got some circuit designs from my Cubesat project, though they are related to solar charging. We can find many generic circuits for battery charging, I'm guessing. The challenge lies with linking the alternator with the charging circuit in the first place.

To make life easy, lets select a ready made portable AC alternator or DC dynamo. Once we get a complete system working we can design our own to improve efficiencies.

For example, this portable DC generator outputs at 1W @ 3.6V. So lets say we extrapolate that to 14V using boosting circuits (to charge the SLA battery), the current would be 71mA. So to fully charge the 4AH battery, it takes:

4000/71 = 51 hours.. I hope I did not do any calculation mistake 😛

We have 10 hours of working time, so we probably need to increase the generation factor by about 5, to 5W.

So guys, try to find a 5 or 6W dynamo or alternator. I know we are cutting the tolerances too close by throwing assumptions here and there, but we can increase power generation and battery capacity next time after we finish this prototype.

[EDIT]
So as a summary, here's what we roughly need for our system:

5/6W dynamo generator -> rectifying/charging circuit -> 12V 4AH SLA battery -> lighting circuit -> 12W CFL

It'll be useful if one of you guys can check the cost of the generator, battery and lightbulb in India. If not, online prices should at least give us a rough estimate. The circuits we can do ourselves.. wont cost that much to fabricate 😀

Cranky, are you alright with this type of system?
@cranky • 08 Aug, 2009 ash:"So lets say we extrapolate that to 14V using boosting circuits (to charge the SLA battery), the current would be 71mA. "


Do lead batteries require 14V?but isn't that they get charges at 2.5V😒?

The summary is just brilliant.I couldn't have thought to this level😁😁

By the way,I was also thinking of an alternative to a dynamo:Micro wind turbines. Can someone comment on the efficiency?
@Ashraf HZ • 08 Aug, 2009
cranky
ash:"So lets say we extrapolate that to 14V using boosting circuits (to charge the SLA battery), the current would be 71mA. "


Do lead batteries require 14V?but isn't that they get charges at 2.5V😒?
The 2.5V value is per cell 😀 We are using a 12V SLA that has around 6 cells (each cell is a nominal 2V) connected in series. Unlike most Lipo batteries where you can charge individual cells, these SLAs only have two terminals.. so we'll need to charge the whole 6 cells. 14V would be the estimated value for daily charging.. which is about 2.3V per cell. Of course, we should add voltage trimmers to adjust the actual voltage needed, which can variate according to circumstances.

By the way,I was also thinking of an alternative to a dynamo:Micro wind turbines. Can someone comment on the efficiency?
[/quote]
Yeah, that would be an interesting alternative provided they are within the a reasonable cost range.
@cranky • 09 Aug, 2009
ash
The 2.5V value is per cell 😀 We are using a 12V SLA that has around 6 cells (each cell is a nominal 2V) connected in series. Unlike most Lipo batteries where you can charge individual cells, these SLAs only have two terminals.. so we'll need to charge the whole 6 cells. 14V would be the estimated value for daily charging.. which is about 2.3V per cell. Of course, we should add voltage trimmers to adjust the actual voltage needed, which can variate according to circumstances.
Didn't know that.Thanks😁
Yeah, that would be an interesting alternative provided they are within the a reasonable cost range.
probably that could be an extension of this work.


Now it is decided.We need to design the circuit.start with charging?
@cranky • 22 Aug, 2009 Now lets place the magnet such that it should touch the rotating part.We will choose the flywheel as stated previously that its rpm is more(by ash😁)

If we make the cylindrical part of dynamo to touch the flywheel(as in case of bicycles),then even rotating the wheel will be difficult.Ultimately,the efficiency of the tailor decreases.

So how about attaching the magnet to the shaft connecting the flywheel and the machine and we can wound the wire around it.Thus,the rotating part would be the magnet and the stator-conductor coils.This way we won't affect the efficiency of the tailor adversely.

What say😒?
@aj_onduty • 13 Jun, 2011
cranky
I guess this is my first proper post.Really glad i found this forum:smile::smile:.

Idea for society(which i don't know if feasible😒):I was just thinking.We see many tailors working at almost every corner of the street during late evenings under tubelights or lamps.Now, if we can generate some amount of energy from the spinning wheel of the sewing machine,I thought we can save energy.By attaching a cyclo dynamo to the wheels we can convert the mechanical to electrical energy(though this may be only a few volts or even lesser).Further,if we place a piezo electric material below the peddle(or whatever you call that-part of the sewing machine near your foot)we can further generate(or convert to be precise)energy.
😕😕
Dear all,
I just read till page 3 of this thread, and I think I must read more, but wait, a few ideas just crash-landed on the front gate of my brain.

First, the best thing you can do use another belt drive from the flywheel (the large wheel. If you call it something else, follow my nomenclature for the time being ) to a generator(Don't get fooled by the name. I am talking about a relatively small generator, may be 24 volts DC.) Else you can use the see saw movement of the pedal to rotate the generator. The see saw movement can be used to rotate it just like a crank-shaft in the combustion engines. To be frank, using piezo-electric crystals is not that feasible(at least for now). The only flip side of the generator thing is that the tailor has to put some extra energy into it. But you know, he gets something in return-free electricity.
Well, if someone is interested in this idea, lets think about implementing it. Please let me know. or if someone has already put forward these ideas, lets do it...
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