Motor's input voltage parameter

[c_mitra]

A one-prop drone? I once imagined I could make a simple one-man helicopter. I would attach a propeller to a motor, hold it over my head, and rise into the air. Just 10 or 20 feet high because of the power cord. As I dreamed, however, I realized that the propeller would spin in one direction, and I would spin in the opposite direction. No go.

Many earlier toy helicopters had this problem. I suggest the original poster to try a simple experiment: fit a motor with a propeller and hang it carefully with a thin thread and power it and observe the dynamics. This is as good an experiment in a proper wind tunnel.

But I would guess that you would rotate in the same sense as the props; just like the body of the helicopter.

Helicopter is more than a motor with a propeller.

 

[c_mitra]

The motor looks like an old design that is heavy, produces low power and has brushes that will soon wear out. My E-fliteRC radio controlled model airplanes, helicopters and drones use modern, lightweight, powerful brushless motors that do not wear out.

Only partly correct.

There are many motors running with brushes continuously for years without interruptions. The electric generators that power our homes also have brushes that carry thousands of Amperes for years. On the other hand, my CD-ROM drive has a fancy motor that spins the CD but none of my CD-ROM drives lasted more than 1-2 years. Brushless motors need electronics to produce AC and the electronics is less reliable than the motor, in general.

power output at max efficiency per unit weight is slowly increasing because of the extensive use of the rare earth magnets. But that pushes up the cost but for the smallest motors.

 

[KlausST]

Hi,

The electric generators that power our homes also have brushes that carry thousands of Amperes for years.

Only partly correct. ;-)

True is, that the generators have brushes.
But it is not for the high current, it is for the DC excitation coil. And the moving contact rings are solid, without segmentation, therefore the wear out is much less than with the segmented DC motor contacts.

The excitation coil is necessary to make the magnetic field variable. During synchronization period (when switch is open) one can adjust the output voltage with it, and when switch is closed (connected to mains grid) one can control cos(phi) with it.

Klaus

 

[rajaram04]

As per the datasheet (thanks albbg!) the motor is rated at 4.5V. The specs are on page 3, left graph. Please refer to the previous page to understand the graph.

ok fine ! i found it its 4.5v done
so now what about maximum current rate for power adapter or battery now for my motor mitra sir ??
please help thanks !!!!

 

[c_mitra]

The information is there in the same datasheet.

At the point of max efficiency, it takes about 0.6A current. The power will be around 2W approx. The torque will be approx 3 mN-m

(I am just reading the same graph). At about 3A current, the efficiency is about 25% and the torque is about 11-12 mN-m.