How to change the direction of a dc motor ?

[danishdeshmuk]

How to change the direction of a dc motor ?

by reversing its field wires or by reversing its armature wires

 

[tpetar]

Hi danishdeshmuk,

You can use H-bridge for this purpose

http://www.robotroom.com/BipolarHBridge.html

H-Bridge with MOSFETs

http://talkingelectronics.com/projects/H-Bridge/H-Bridge-1.html


or

This simple two transistor control :

**broken link removed**

http://www.ecelab.com/circuit-motor-control-1.htm

 

[rfredel]

Hello danishdeshmuk,

yes, you can change the direction of a DC - motor by changing the field wires or by changing the armature wires.

Only take care, that you change only the field or the rotary field. If you change both at the same time, you don't change the direction.

Regards

Rainer

 

[tpetar]

You can try this circuit also :



**broken link removed**

Here, S1 and S2 are normally open , push to close, press button switches. The diodes can be
red or green and are there only to indicate direction. You may need to alter the TIP31 transistors
depending on the motor being used. Remember, running under load draws more current. This
circuit was built to operate a small motor used for opening and closing a pair of curtains. As an
advantage over automatic closing and opening systems, you have control of how much, or how
little light to let into a room. The four diodes surriunding the motor, are back EMF diodes. They
are chosen to suit the motor. For a 12V motor drawing 1amp under load, I use 1N4001 diodes.

 

[danishdeshmuk]

isn't there any simple method apart from the circuits ??

reversing the wires of field or armature would result any reversing of direction ?

 

[godfreyl]

isn't there any simple method apart from the circuits ??

You could just use a DPDT switch, if you want to reverse the motor manually.

 

[danishdeshmuk]

how to wire this DPDT switch so that reverse the direction of the motor manually ?

 

[rfredel]

Hello danishdeshmuk,

in the attached circuit you see, how to wire the motor.



Regards

Rainer

 

[danishdeshmuk]

would you indicate where to connect field wires & where to armature wires ?

- - - Updated - - -

how to distinguish between the field wires & armature wires with DMM ?

 

[godfreyl]

how to distinguish between the field wires & armature wires with DMM ?

It doesn't matter which is which. You just need to reverse one of them.

 

[7102]

use this circuit for forward & reversing of dc motor

 

[rfredel]

Hello danishdeshmuk,

here in Europe the marking of the connection terminals for the armature wires are A1 and A2. In earlier time it was A and B. With a DMM you can measure the resistance between this terminals. If you turn the armature ve slowly, you can see, when the commutator is changing the winding.

For a shunt-wound motor, the field winding terminals are named E1 and E2. The old names are C and D. The resistance of the winding is high. The current through this winding is low against the armature. If you can see this wires, this wires are thinner then from the armature.

For a series motor the terminals are named D1 and D2, befor E and F. The resitance of this winding is low, because the same current is pass as in the armature. Also the connection wires have the same diameter then the armature.

I don't know, if the marking is worldwide like here in Europe.

Regards

Rainer

 

[danishdeshmuk]

Would In all three types of dc motor by rotating the armature the resistance values of armature wires be changed ???

- - - Updated - - -

you didnt tell about the names whether armature wires or field wires for the series motor .

D1 & D2 belong to armature or field ????

 

[rfredel]

Hello danishdeshmuk,

Would In all three types of dc motor by rotating the armature the resistance values of armature wires be changed ???

Yes the resistor will change every time, because the carbon contact will shorten two contacts of the armature.

you didnt tell about the names whether armature wires or field wires for the series motor .

The names of the armature is everytime the same (A1 & A2). The field wires for the series motors are named D1 & D2. The names for the shunt-wound motor is E1 & E2.

Here is a updated circuit.




Here I'll give you a security advice to connect a shunt motor:

Take care, that the field winding never will be disconnected from the main line, because the motor speed will rise up until the Motor is distroyed.

Regards

Rainer

 

[Raza]

Simple is that if you change the supply polarity of a DC motor, the spinning direction of the motor will change. Different mechanism can be used to do this for Series or Shunt wound motors.

 

[phatcreators]

from where to change the polarity of a dc motor ?

 

[tpetar]

Best to put AC on it and we will se where he whant to go. :smile:



Like in previous post we said swaping wires will do the job, if you need some direction to be fixed for your needs, but if you need some taster/switching control of your motor use H-bridge.

One more thing you should check if there is cooling fans on rotor, and check their direction of pushing air.

 

[rfredel]

Hello Raza,

that will only function, if you have a permanent magnet field, else the direction will not change, because field and armarture have the same direction again.

Series motors and also shunt motors are use for AC in maschines like drills, hairdryer and trains. I think, you'll see, that your drill will run in same direction equal you put your plug in the socket.

Regards

Rainer

- - - Updated - - -

Hello tpetar,

but if you need some taster/switching control of your motor use H-bridge.

yes, you can do by a H-Bridge, like you draw it in post #2 and #4 but you need a permanent field. You only draw the armature, what is right. The permanent field can be produce by a permanent magnet or a electric magnet.

Regards

Rainer

 

[Raza]

How to change the direction of a dc motor ?

by reversing its field wires or by reversing its armature wires

It would be much easier to explain if the usage and type of motor is explained.

 

[rfredel]

Hello Raza,

it's not necessary to know the useage and the type of motor, because the question was a simple circuit for the changing of the direction.

The simple way to change direction is to do it with a switch. If you need special applications, there will be circuits enough.

Regards

Rainer