The reason being it is a Series field motor and operates in a run away condition normally, with double the voltage it attempts double the RPM, This is why the large shunt wound-field DC motors had field loss protection, as this loss would cause a run-away condition, often to destruction.My observation has been that when a 120 volt shop vac is plugged into a 220 volt outlet and switched on, that it screams instead of just roars.
Another point this made me consider; higher current may be beyond the switches that are used to control the motors. As I recall, the switches in one of my kids toys - got it second hand - were pretty badly burned up. Possible someone tried a higher voltage, which lead to a higher current, which lead to greater arcing and burning of the switches.The new motors might have a higher weight, not fit on the same place, the higher current is probably not supported by the electronics and I don't know if there are any legal concerns as the vehicle has to be under certain power, speed and etc.
One possibility that can provide better performance is to apply an anti-slip treatment to the wheels. On my grand-nephew's tractor the wheels slip a lot when it starts.Ok guys. Looks like I will be leaving it as is. I wanted about 6 mph as it is not really brisk walking speed as is.
This was bought at smyths toys and is the bmw i8 trin motor 12v model.
They do the 6v single motor model but I believe it is the same motor in 1 wheel only and a 6v battery. It also has 1 relay and not 2.
I just wanted to have the car but a little quicker now that he is older.
I figure, torque is proportional to current, and max RPM proportional to voltage. I think the TS should leave the motors alone, and upgrade the battery to lithium. Lower internal resistance would give more torque, and 4 cells would give from 16.8v - 14.8v, giving a little more speed, without frying anything. He could also use even more cells along with a PWM motor speed controller. Full power would only be used intermittently. You have to make sure to buy the real brand name cells, to get the max amps. There are a lot of fakes out there! (which I have bought by mistake)Most of you guys are just too funny for words. Your assumptions on how PM DC motors work.
I certainly agree on this one, S.B., almost to the point of making remarks about other's concerns. But I will not make fun of anybody this time.Most of you guys are just too funny for words. Your assumptions on how PM DC motors work.
by Jake Hertz
by Jake Hertz
by Aaron Carman