Electric motors. 12 volt.

[ukracer]

What is the outcome of running a 12 volt toy car motor at 6 volts.
I assume the speed would be reduced to half?

What would happen to the torque?

I ask because we have a number of electric motors from our RC days.
We also have a child's sit in electric car that is all 6 volts.

Now whilst we can swap out all the electronics and use a 12 volt battery.

But I am wondering about the effects of running a lower turn motor at reduced voltage, whether it will produce enough torque being a 6 volt motor. Plus increased speed as we intend to use a 10 turn instead of a 27 turn.

 

[gaz1]

unless the motor is toquey at 6 volts it wont pull enough or push the vehicle along

i had one for both my kids and it didnt like the 6 volt batterys on a 12v motor in end had to go back up too a proper battery

you can go down from a 12 to a 6 rather well though and it will supply longer running times but the resistors need to be air cooled otherwise they over heat

 

[eLuSiVeMiTe]

Gearing would play a big part in an RC car both in the diffs and transfer boxes especially with low turn motors to keep the torque up.

I don't believe the increase in speed is linear though.


You would be increasing the speed of the motor a lot going from 27t to 10t and are already going to be losing some torque before dropping volts.

Am assuming 3slots?

 

[ukracer]

Gearing would play a big part in an RC car both in the diffs and transfer boxes especially with low turn motors to keep the torque up.

I don't believe the increase in speed is linear though.


You would be increasing the speed of the motor a lot going from 27t to 10t and are already going to be losing some torque before dropping volts.

Am assuming 3slots?

3 slots???

 

[ukracer]

Gearing would play a big part in an RC car both in the diffs and transfer boxes especially with low turn motors to keep the torque up.

I don't believe the increase in speed is linear though.


You would be increasing the speed of the motor a lot going from 27t to 10t and are already going to be losing some torque before dropping volts.

Am assuming 3slots?

This is only a small ride on car.

Unlike an RC car it has no speed controller perse. It's merely a switch.
On and off when used manually.
It also seems to be the same when used with the mini remote.
I do need to investigate how the steering works.
Obviously when grandson is in the car it's controlled by the wheel.
But remotely it seems to be in two stages. 2 left and two right.

 

[eLuSiVeMiTe]

3 slots???

Slots for the windings.

Eg 5 slot 15t is probably equal to a 3slot 27t motor

 

[eLuSiVeMiTe]

This is only a small ride on car.

Unlike an RC car it has no speed controller perse. It's merely a switch.
On and off when used manually.
It also seems to be the same when used with the mini remote.
I do need to investigate how the steering works.
Obviously when grandson is in the car it's controlled by the wheel.
But remotely it seems to be in two stages. 2 left and two right.

What's the original motor specs. Better off trying to match up

 

[optima21]

there is no way you'll know how it will perform unless you try it, but running a 12v motor on 6v will probably give you very little torque, but that will depend on the motor spec. for a given voltage if a motor has a lower rpm, it will have a higher torque (and more windings) or thats what Ive found with the small low voltage motors that Ive been playing with.

 

[premmington]

Slots for the windings.

Eg 5 slot 15t is probably equal to a 3slot 27t motor

+1 for above

 

[GRW]

Won't dropping to 6v for the same load on a 12v motor result in double the current and heat - and cook the motor?

 

[m_c]

For most motors,

Current = Torque
Voltage = speed.

So halving the supply voltage will roughly half the maximum speed.
A motor will only draw current proportional to the torque being asked off from the motor, so regardless of supply voltage, you should still limit the Current.

 

[voipio]

Won't dropping to 6v for the same load on a 12v motor result in double the current and heat - and cook the motor?

If "same load" refers to torque e.g. lifting a given weight via a fixed diameter pulley then, in a permanent field magnet type motor, delivering that torque will require the same current through the windings, so the heat dissipated in the rotor windings should be the same. The motor will lift the load more slowly using a 6V supply, compared to a 12V supply, because the back e.m.f. will reach 6V at a lower speed than at 12V, and lifting the weight would take longer, so more heat would be dissipated moving the weight over a given distance, when running off 6V compared to 12V. If the torque was being delivered constantly, the heat dissipation would be the same, more or less, though in reality, bearing friction losses would be higher when running off 12V .