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Electric car con
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Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day |
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By *ad NannaWoman
over a year ago
East London |
You can't create energy out of thin air, you have to transfer it.
Maybe if you set off at the top of a hill every morning you can use gravitational energy to charge the battery.
You'd have to push the car back up the hill every night though. |
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A dynamo/alternator requires an energy source to work it and nobody has invented one that produces as much energy as it consumes, your battery capacity will be extended but ultimately you will still have to stop and charge
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"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day"
If this worked, you’d have invented a perpetual motion machine. Sadly, because energy transfer always has inefficiencies, you can’t generate enough electricity.
Electric vehicles do have regenerate braking though, so instead of pressing the brake pedal and friction being thrown away as wasted heat, the power goes back into the batteries. |
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An electric car will charge when travelling downhill, where we live its all mountains and let's say I use 4 percent to climb one side I will gain back 1 maybe 2 percent back to the battery level on descent.
It's has three different modes of drive too and when you lift off the accelerator depending on which mode you select it will put charge back to the battery, where the most economical mode will feel like quite hard braking as it's putting more charge back and the normal mode only puts charge back when you choose to brake yourself. |
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I have fitted a dynamo (actually a DC washing machine motor used in reverse) to an exercise bike. Pedalling quite hard I can light a 60 watt headlamp bulb.
I don't think I would get very far charging a car with it!
Electric cars can usually make some use of regenerative braking when going down hill or coming up to a halt.
Otherwise dream on where free energy is concerned, particularly until lossless conversion is discovered.
Now, here's an idea, I might fit an old bike dynamo to rub against a rear tyre wall on my car to help charge my phones! |
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"I have fitted a dynamo (actually a DC washing machine motor used in reverse) to an exercise bike. Pedalling quite hard I can light a 60 watt headlamp bulb.
I don't think I would get very far charging a car with it!
Electric cars can usually make some use of regenerative braking when going down hill or coming up to a halt.
Otherwise dream on where free energy is concerned, particularly until lossless conversion is discovered.
Now, here's an idea, I might fit an old bike dynamo to rub against a rear tyre wall on my car to help charge my phones!"
Would the friction of that dynamo just use more of the cars battery any way so pointless |
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By *TG3Man
over a year ago
Dorchester |
"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day"
exactly  |
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"I have fitted a dynamo (actually a DC washing machine motor used in reverse) to an exercise bike. Pedalling quite hard I can light a 60 watt headlamp bulb.
I don't think I would get very far charging a car with it!
Electric cars can usually make some use of regenerative braking when going down hill or coming up to a halt.
Otherwise dream on where free energy is concerned, particularly until lossless conversion is discovered.
Now, here's an idea, I might fit an old bike dynamo to rub against a rear tyre wall on my car to help charge my phones!
Would the friction of that dynamo just use more of the cars battery any way so pointless"
I was thinking more about how I could wear out the tyre prematurely! |
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By *TG3Man
over a year ago
Dorchester |
"And here's me. I thought this is exactly how hybrids worked. They use petrol until they electric battery chanrges then switches to electric...
Isn't this done with a dynamo?"
yes but fuel as well  |
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By *oodmessMan
over a year ago
yumsville |
"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day"
Because you are the engine powering the bike. Your energy is powering the wheel and the light.
I have wondered the same thing though but with larger vehicles - trains maybe HGV's. Why cant batteries be under some carriages and regeneration come from the wheels of other carriages. |
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"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day
Because you are the engine powering the bike. Your energy is powering the wheel and the light.
I have wondered the same thing though but with larger vehicles - trains maybe HGV's. Why cant batteries be under some carriages and regeneration come from the wheels of other carriages."
You would have to find a source of energy that creates more than it consumes, I don’t believe this has been achieved yet. |
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"And here's me. I thought this is exactly how hybrids worked. They use petrol until they electric battery chanrges then switches to electric...
Isn't this done with a dynamo?yes but fuel as well "
I'll take that over the Flintstones approach  |
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When at uni we tried this. We made a buggy with a 12 volt motor, a car battery and an alternator. We did the calcs and knew it would eventually run out of energy and it did.
There’s too many losses in the system to make it work.
The alternator has both magnetic and power losses (P=I2xR).
The battery has resistive losses.
The motor has the same losses as the alternator.
The cables to make it all work have resistive losses.
All these losses consume energy and eventually the battery gets to a state of discharge where it can’t power the motor anymore and has to be recharged.
As the battery is discharged the losses increase. |
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I think you'll find the dynamo needed you to pedal or go downhill and probably produces about 5 or 10 watts which is just about enough to power one of those little torch batteries you used to get in bike lights. I imagine an LED light would be much brighter nowadays  |
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Not sure if the people that live in the Maldives would agree with you or a bit nearer to home the peeps that live on the East coast of the UK that are seeing their houses washed away and just for the record I am no ECO warrior and think JSO people should be put away for a while to cool off a bit, but I have gone solar and the fact I have had virtually no power bill so far this year is pretty awesome and I will soon be getting around for free too with a Corsa E. What's not to like about that.
If only the people that had the money to do this stuff would stop burying their heads up their You know whats and help out a bit but by investing a bit of their own dosh in this stuff instead of expecting the government to do everything, but hey ho no one wants to take responsibility. |
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"And here's me. I thought this is exactly how hybrids worked. They use petrol until they electric battery chanrges then switches to electric...
Isn't this done with a dynamo?"
Pretty much.
Some (series hybrids) use petrol engines to charge batteries via an alternator (like a dynamo, but more reliable), and then that energy to drive an electric motor.
Others use a petrol engine to drive the wheels, and use the alternators* to slow the car down instead of braking (with conventional brakes too for heavy braking) and then use that energy to power motors that assist the petrol engine (or run by themselves at low speed).
*Actually the motors running in reverse |
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Basically, a dynamo is a device made up of two parts. A static coil (stator) and a rotor which rotates within the stator.
The dynamo is fixed to the bicycle forks in a position where the rotor wheel of the dynamo is touching the bicycle tyre. When the bicycle is moving the rotor rotates within the stator which in turn produces electricity. In this case the bicycle is called the prime mover. The cyclist is the energy source needed to make the bicycle move in the first place. A dynamo produces unregulated dc electricity. In layman's terms, the faster the cyclist is pedling, the higher the voltage from the dynamo and the brighter the bicycle lights.
A generator has two basic moving parts. The prime mover, usually a petrol or diesel engine, attached to an alternator. The alternator produces ac power which is regulated to produce the required voltage. Most commonly 240vac which is the normal domestic voltage, or 415vac which is more commonly used for industrial applications.
Whatever device is used to produce electricity, it has to have a prime mover and the prime mover requires an energy source to drive it. Be it petrol, diesel, wind, water or human, ie the cyclist.
I shall cover battery power in a future tutorial
Now, please feel free to discredit any or all of that as I'm sure some on here no doubt will.
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"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day"
Nice idea..
And i agree theres a lot of smoke and mirrors in the car and especially electic car world. But energy can be neither created nor destroyed. You have to have some energy to propel your car to turn your dynamo to charge your battery... Unless you are fred flintstone and pedalling it. |
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Bicycle dynamos are simple alternators.
They usually consist of a magnet rotating inside a field coil system to produce an alternating supply. No brushes are even needed.
Can't get much simpler than that but in order to charge a battery at least one diode would be needed to create DC and also to prevent the battery discharging back into the dynamo.
My repurposed washing machine motor, which works well as a DC generator, uses a high grade cylindrical ceramic magnet with a wound armature rotating inside it and the energy is transferred via brushes. That's when things start getting complicated compared to the humble bicycle dynamo.
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"Basically, a dynamo is a device made up of two parts. A static coil (stator) and a rotor which rotates within the stator.
The dynamo is fixed to the bicycle forks in a position where the rotor wheel of the dynamo is touching the bicycle tyre. When the bicycle is moving the rotor rotates within the stator which in turn produces electricity. In this case the bicycle is called the prime mover. The cyclist is the energy source needed to make the bicycle move in the first place. A dynamo produces unregulated dc electricity. In layman's terms, the faster the cyclist is pedling, the higher the voltage from the dynamo and the brighter the bicycle lights.
A generator has two basic moving parts. The prime mover, usually a petrol or diesel engine, attached to an alternator. The alternator produces ac power which is regulated to produce the required voltage. Most commonly 240vac which is the normal domestic voltage, or 415vac which is more commonly used for industrial applications.
Whatever device is used to produce electricity, it has to have a prime mover and the prime mover requires an energy source to drive it. Be it petrol, diesel, wind, water or human, ie the cyclist.
I shall cover battery power in a future tutorial
Now, please feel free to discredit any or all of that as I'm sure some on here no doubt will.
"
Pretty much, although at the risk of being pedantic the voltage of a dynamo is a function of the coils; pedalling faster increases the available current rather than the voltage. |
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"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day"
Because if that was the case the cars would be super expensive, if you want to make money you make the vehicles readily available and the fuel costly.
The mr |
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"Can someone explain to me please
When i was a kid i had something called a dynamo fixed to my bike. As the wheel turned it would power the lights, no need for a battery
So why can we not make electric cars with something like this rather than charging each day
Because if that was the case the cars would be super expensive, if you want to make money you make the vehicles readily available and the fuel costly.
The mr "
Another good reason why not is that the concept doesn't make sense! |
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"Except that the current is relative to the voltage. Basic ohms law.
But I take your point.
V = IR "
Ohms Law
I = V over R
R = V over I
V = I x R
When voltage is applied to a resistive load, current will flow through that load. The amount of current flowing through that load depends on the resistance of the load and value of the voltage applied to it. |
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"Except that the current is relative to the voltage. Basic ohms law.
But I take your point.
V = IR
Ohms Law
I = V over R
R = V over I
V = I x R
When voltage is applied to a resistive load, current will flow through that load. The amount of current flowing through that load depends on the resistance of the load and value of the voltage applied to it."
The current DRAW is proportional to voltage divided by resistance; current SUPPLIED will be a combination of draw and the power capacity of the supply (which is why tasers generally don’t kill people, despite vast voltages). |
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Hell fire.
The energy being consumed in an electric car is replacing losses to drag, heat and friction. This is why regenerative braking can’t be 100% effective.
Imagine riding a bike if it helps. You’re overcoming the wind.
You pedal energy in to gain speed, then you’ve got momentum.
If you stop pedalling then you slow down mostly due to wind resistance. Tiny bit of friction in the hubs.
When you brake, that energy in your momentum is converted into heat by the brakes causing the tyres to act against you by friction with the ground.
Wind resistance increases by the square of the speed, so travelling at 80 mph uses a lot more energy than travelling at 70mph simply because of the drag.
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"Just get wrist dynamos fitted to all the guy's wanking on fabs,one day's wanking would probably charge all the the EVs in the UK for a year. "
Wankers driving electric vehicles...? Did you just say that? |
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