Electrical Project - Advice Needed
Discussion
Im after a bit of advice on a project that i am currently working on.
Basically i have a motor powered by a 12v battery which turns a shaft through a gearbox.
What i want to do is use an alternator or generator which is also attached to the shaft via a gearbox to charge the 12v battery.
Is this possible? Can i simply use another 12v powered motor and switch the polarity around to use it as a generator. I am okay with the mechanical side of the project but just need a bit of advice with the electrical side of this.
Thanks in advance,
Ryan
Basically i have a motor powered by a 12v battery which turns a shaft through a gearbox.
What i want to do is use an alternator or generator which is also attached to the shaft via a gearbox to charge the 12v battery.
Is this possible? Can i simply use another 12v powered motor and switch the polarity around to use it as a generator. I am okay with the mechanical side of the project but just need a bit of advice with the electrical side of this.
Thanks in advance,
Ryan
Im after a bit of advice on a project that i am currently working on.
Basically i have a motor powered by a 12v battery which turns a shaft through a gearbox.
What i want to do is use an alternator or generator which is also attached to the shaft via a gearbox to charge the 12v battery.
Is this possible? Can i simply use another 12v powered motor and switch the polarity around to use it as a generator. I am okay with the mechanical side of the project but just need a bit of advice with the electrical side of this.
Thanks in advance,
Ryan
Basically i have a motor powered by a 12v battery which turns a shaft through a gearbox.
What i want to do is use an alternator or generator which is also attached to the shaft via a gearbox to charge the 12v battery.
Is this possible? Can i simply use another 12v powered motor and switch the polarity around to use it as a generator. I am okay with the mechanical side of the project but just need a bit of advice with the electrical side of this.
Thanks in advance,
Ryan
What you are saying is you want to continuoisly recharge the battery by discharging it into a motor to drive a generator, hmmmm...
Of course you can turn a DC motor into a generator, alternators do it more efficiently and run a constant voltage, Dynamo's need voltage regulators to work properly as increasing rpm makes the voltage go up.
I can see what you are trying to achieve but the laws of physics and the efficiencies of the equipment will not mean free energy.
Of course you can turn a DC motor into a generator, alternators do it more efficiently and run a constant voltage, Dynamo's need voltage regulators to work properly as increasing rpm makes the voltage go up.
I can see what you are trying to achieve but the laws of physics and the efficiencies of the equipment will not mean free energy.
Simpo Two said:
You want to use a 12V battery to drive a motor to drive a generator to charge a 12V battery?
You could dispense with the motor, generator and one battery, and keep the other battery shiny and fully-charged on a shelf
Yes i want to charge the same 12V battery that is powering the motor so there is only one battery is involved. Similar to the setup in a car with the battery and the alternator charging it as the engine is running.You could dispense with the motor, generator and one battery, and keep the other battery shiny and fully-charged on a shelf
ryanc1993 said:
Simpo Two said:
You want to use a 12V battery to drive a motor to drive a generator to charge a 12V battery?
You could dispense with the motor, generator and one battery, and keep the other battery shiny and fully-charged on a shelf
Yes i want to charge the same 12V battery that is powering the motor so there is only one battery is involved. Similar to the setup in a car with the battery and the alternator charging it as the engine is running.You could dispense with the motor, generator and one battery, and keep the other battery shiny and fully-charged on a shelf
ryanc1993 said:
Yes i want to charge the same 12V battery that is powering the motor so there is only one battery is involved. Similar to the setup in a car with the battery and the alternator charging it as the engine is running.
Ah I see. Well if you turn a motor mechanically, it generates electricity - I think, if I recall my O-level physics. Right-hand rule, back EMF and all that.ryanc1993 said:
Yes i want to charge the same 12V battery that is powering the motor so there is only one battery is involved. Similar to the setup in a car with the battery and the alternator charging it as the engine is running.
Assuming this is genuine and not a troll, I get the feeling you aren't going to accept the truth from other people, so go ahead and give it try. I suspect almost everyone with any scientific interest has 'invented' this amazing scheme in their youth (I can clearly remember trying this when I was about 7 or 8 years old).A permanent magnet, brushed motor can certainly work as a (fairly inefficient) DC generator. Obviously the output from the generator will have to be at a higher voltage than the battery in order to charge the battery, otherwise the battery will be powering it as a motor. This means that given two identical motors, the one acting as a generator will have to be turned faster than the one driving it, so you gearbox has to step up the speed rather than reduce it. It still won't work though.
Fairly pointless now, but fo rthe record:
If you use a synchronously rectified pulse width modulated H bridge (MOSFETS as switches) driving a normal brushed motor, you can easily drive a motor in all four quandrants (FWD Motoring, FWD Absorbing, REV Motoring, REV Absorbing) and you can do this at all shaft speeds for which the system (Motor speed constant x battery voltage) is capable.
In effect, couple your motor directly to a large inertia, spin up that inertia, taking power from the battery, to max speed, then use the drive in "regen" to slow the inertia back down again. Typical round trip efficiency will be circa 50% (i.e. every time you do it, you'll "loose" 50% of the total energy cycled.
With a synchronously rectified switching bridge, the motors inductance acts to smooth the phase current, and in effect acts like a buck / boost convertor, allowing the system to either drive or regenerate (even if the motor's Bemf is lower than the battery voltage)
Anyway, pointless meanderings over. ;-)
If you use a synchronously rectified pulse width modulated H bridge (MOSFETS as switches) driving a normal brushed motor, you can easily drive a motor in all four quandrants (FWD Motoring, FWD Absorbing, REV Motoring, REV Absorbing) and you can do this at all shaft speeds for which the system (Motor speed constant x battery voltage) is capable.
In effect, couple your motor directly to a large inertia, spin up that inertia, taking power from the battery, to max speed, then use the drive in "regen" to slow the inertia back down again. Typical round trip efficiency will be circa 50% (i.e. every time you do it, you'll "loose" 50% of the total energy cycled.
With a synchronously rectified switching bridge, the motors inductance acts to smooth the phase current, and in effect acts like a buck / boost convertor, allowing the system to either drive or regenerate (even if the motor's Bemf is lower than the battery voltage)
Anyway, pointless meanderings over. ;-)
As others have said, what you are trying to do is create free energy, and it appears you're doing this without any knowledge of how energy, or electricity works
To put it simply the whole electrical/mechanical chain is using energy, which is coming from the battery. The power available at the end of the chain is less than is being drawn from the battery.
If instead of your set up you had a charged battery>motor>generator>flat battery, and you set that going, it would charge the battery but when the first battery ran out of power, the one at then end would only be partially charged. The rest of the energy would have been lost to the conversions.
The same principal would appy with a loop back to the original battery.
To put it simply the whole electrical/mechanical chain is using energy, which is coming from the battery. The power available at the end of the chain is less than is being drawn from the battery.
If instead of your set up you had a charged battery>motor>generator>flat battery, and you set that going, it would charge the battery but when the first battery ran out of power, the one at then end would only be partially charged. The rest of the energy would have been lost to the conversions.
The same principal would appy with a loop back to the original battery.
I think people are being a bit thick on this thread.
Nowhere does the OP state what the gearbox is driving. It could be used to propel a vehicle, for example.
Now in such a case, as well as speeding up, you might want to slow the vehicle down too. in which case it is really rather practical to use the momentum of the energy to turn a motor/generator and charge the battery. Of course this kind of idea is widely implemented and used in lots of vehicles.
so I don't think the OP is trying to break the laws of physics, or generate free energy, but rather has a practical question for a practical purpose that everybody has overlooked.
Nowhere does the OP state what the gearbox is driving. It could be used to propel a vehicle, for example.
Now in such a case, as well as speeding up, you might want to slow the vehicle down too. in which case it is really rather practical to use the momentum of the energy to turn a motor/generator and charge the battery. Of course this kind of idea is widely implemented and used in lots of vehicles.
so I don't think the OP is trying to break the laws of physics, or generate free energy, but rather has a practical question for a practical purpose that everybody has overlooked.
RealSquirrels said:
I think people are being a bit thick on this thread.
Nowhere does the OP state what the gearbox is driving. It could be used to propel a vehicle, for example.
Now in such a case, as well as speeding up, you might want to slow the vehicle down too. in which case it is really rather practical to use the momentum of the energy to turn a motor/generator and charge the battery. Of course this kind of idea is widely implemented and used in lots of vehicles.
so I don't think the OP is trying to break the laws of physics, or generate free energy, but rather has a practical question for a practical purpose that everybody has overlooked.
I think it's perhaps you who has not read the OP correctly. He's already using a DC motor to provide the mechanical power. Why would you add yet another DC motor to use as an inefficient generator when you could use the existing motor for regenerative braking? It's very clear what he's trying to achieve.Nowhere does the OP state what the gearbox is driving. It could be used to propel a vehicle, for example.
Now in such a case, as well as speeding up, you might want to slow the vehicle down too. in which case it is really rather practical to use the momentum of the energy to turn a motor/generator and charge the battery. Of course this kind of idea is widely implemented and used in lots of vehicles.
so I don't think the OP is trying to break the laws of physics, or generate free energy, but rather has a practical question for a practical purpose that everybody has overlooked.
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