Reversible DC motor

[roythegrass]

Hi Folks

I’m buying a small 12v DC motor which is required to rotate in both directions.Some of these motors are sold as ‘reversible’ whilst others don’t mention this in the description.
Aren’t all of these motors reversible if the polarity is swapped?
Thanks
Roy

 

[Jackrae]

If they're permanent magnet and brushed, yes they are, BUT most decent motors have the brushes set at a slight angle or off centre to the commutator to enhance performance. If used in reverse they may not be as efficient and the brushes may wear faster than normal.

 

[ericmark]

If the field is wound and not a permanent magnet swapping polarity will still drive motor in the same direction, most motors driving wheel chairs, mobility scooters and like will allow you to swap polarity of field without swapping polarity of the armature to reverse them.

Some so called DC motors are not, even the little fans in computers are AC motors and inside the motor is a tiny inverter turning DC to AC. Car heater motors years ago where done both with permanent magnets and wound field coils they looked the same but one would reverse the other would not.

Today electric drills have electronics, but years ago an electric drill would work on AC or DC it did not matter. They had a wound field coil.

 

[winston1]

Today electric drills have electronics, but years ago an electric drill would work on AC or DC it did not matter. They had a wound field coil.

Well yes in theory. I knew someone who had 110 volt drill and decided to run it on a DC power supply. There was increased sparking at the commutator and the trigger switch did not last long as it was an AC switch and didn't like the arc every time it was released.

 

[Jackrae]

Without adding tangents or confusion to the matter, I stand by my statement "permanent magnet and brushed"

 

[ericmark]

Aren’t all of these motors reversible if the polarity is swapped?

No.

Without adding tangents or confusion to the matter, I stand by my statement "permanent magnet and brushed"

But that does not include all motors.

 

[bernardgreen]

Adding to the confusion... There are reversible wound field motors which full wave rectify the supply to the field windings.

If the OP was to offer some information about the size of the motor and/or the application then more appropriate advice could be forthcoming.

 

[Jackrae]

"I’m buying a small 12v DC motor..."
Think that should cover around 99% of non-specific enquiries

 

[roythegrass]

This is the motor:
http://www.rfcontrolsystem.com/index.php?main_page=product_info&cPath=470_453_462&products_id=1400

 

[EFLImpudence]

 

[Jackrae]

As EFL has illustrated, the manual quite clearly states the subject motor is reversible.
Pity the OP failed to read it - or was he enquiring about DC motors that do not specifically state they are reversible.
Ah well, that was fun !

 

[ban-all-sheds]

Hi Folks

I’m buying a small 12v DC motor which is required to rotate in both directions, and which does so. Some of these motors are sold as ‘reversible’ whilst others don’t mention this in the description, but I am not buying one of those, I am buying one which is reversible.

Aren’t all of these motors reversible if the polarity is swapped?

 

[ban-all-sheds]

Mainly used for remote-controlled car, electric motorbike, ATV, Kart, robot, rolling blind and electric projector, etc.

What do they mean by those?

 

[SimonH2]

What do they mean by those?

Perhaps they simply mean a motorbike, ATV, Kart which has an electric motor rather than an engine. Actually quite common.