Final Year Project-How to make a RF remote control car that can power 72v motor

[roylimyk]

hei ..i need help on my final year project..during the previous years i have made a RF remote control car....but i found out that the motor is not able to move the car ...i have tried several ways like adding a voltage doubler or a circuit doubler to increase the voltage to the motor but it doesent work ..the motor is a 72v high torque motor...can anyone help me??

[newInRobotics]

Why not to put 72V battery? 

[roylimyk]

thats a little big....how can i fit a 72 volt battery in to the car??would it be heavy?

[newInRobotics]

Right, first we need to clarify few things:

• What's the size of the car? Pictures would help. If it's a full size car (the one that You'd drive on a street), putting 72V battery is peanuts.
• Whta's the size of the motor? Datasheet and pictures would help.

If it's a small car, then why do You need such high torque and high voltage motor to drive it? Can You use something smaller? Are You sure it's 72V and not 7.2V?

[roylimyk]

Right, first we need to clarify few things:

• What's the size of the car? Pictures would help. If it's a full size car (the one that You'd drive on a street), putting 72V battery is peanuts.
• Whta's the size of the motor? Datasheet and pictures would help.

If it's a small car, then why do You need such high torque and high voltage motor to drive it? Can You use something smaller? Are You sure it's 72V and not 7.2V?

http://www.genetron.com.sg/files/Motor%20Catalog%20050908.pdf
there this is the motor..look at the high torque motor
3 duty pole dc motor
6~72v motor
speed of motor 7500-8900
current 0.7-7.5A

[Soeren]

Hi,

http://www.genetron.com.sg/files/Motor%20Catalog%20050908.pdf
there this is the motor..look at the high torque motor
3 duty pole dc motor
6~72v motor
speed of motor 7500-8900
current 0.7-7.5A

It's a typo in the "catalog"!!
It should probably be 6-7.2V
It's a little smaller than the ones used in cordless drills (which are closer to 300g).
If it runs reliably at 6V, 72V would burn it out instantly and besides, 72V is far beyond the safe limits.
The "3-pole" refers to magnetic poles.

You need gear reduction (say 20:1 to 50:1) to get the needed torque, or the motor just stalls and draws a lot of current (possibly heating up to the point where it burns its windings)!
Stall current may likely be up to 15..20A.

Your battery needs to be able to supply 7.5A into a 1 Ohm load and your motor controller needs to be able to handle this as well (of course).