shunt motors, series motors...dc motor

[fabbie]

after learning about shunt motors and series motors in my class lectures, ONE BIG question came into my mind. How do i know whether that particular motor is shunt or series(especially since my 12VDC motor was picked up from a car wreakage facility)? I mean all this while i have been just plainly been calling it DC motor. Does it even matter if its shunt or series?

 

[JimB]

after learning about shunt motors and series motors in my class lectures,

Does it even matter if its shunt or series?

So, you learned "all about" DC motors and you are now asking "does it matter which type?"

Methinks that you did not learn all that much.

JimB

 

[fabbie]

LOL. OK OK. Let me rephrase.
Currently, i have a dc motor. All i do is connect one wire to a positive and the another the negative. So it seems to me it doesnt matter what type of motor im using.
Hmm.. but then again since im using such a small powered motor, the difference wouldnt be obvious.
AAhhh...never mind...just forget i asked this question .

 

[JimB]

A series motor will give a very high torque at low speeds and so they are often used as starter motors in car engines. If you run a series motor with no load, it will run at a very high speed which will fall rapidly as the load is applied.

A shunt motor will run at a (fairly) constant speed irrespecive of whether the load is light or heavy.
The speed of a shunt motor is proportional to the voltage applied to the rotor.
The speed of a shunt motor can also be varied by altering the current flowing in the field coils.

A permanent magnet motor will have characteristics similar to a shunt motor.

JimB

 

[Styx]

Series and shunt brushed DC are to do with how the stator field is generated.

A shunt wired (ie the stator winding electrcally in parallel with the rotor winding) will have a constant field strength independant of the load (to some extent).

A series wired, as the name implies has the stator winding is series with the rotor winding. Thus the strength of the stator field will be dependant on the load.

Both have their advantages and diadvantages. I personally never liked motors sold like that. I liked the ones where you got 4 terminal's and you could choose how to wire it up (shunt or serieS) OR use a separate supply for the stator and do field weakening

 

[TheOne]

And a compound-wound motor will give you the best of both characteristics.

**broken link removed**