shunt wound motor control 1

[richard29e5]

Have a small 1/50th shunt wound gearmotor with output speed of 57 rpm. I want to just run it at constant speed 57rpm output. I have a controller that is meant for a PM motor.
It has 90v dc out and a pot. Could I use this simple controller and connect both the armature and field to the 90 v source and just not vary the pot. Field is rated for 100v. What I be creating a dead short? Your help is appreciated.
richard29e5

 

[Skogsgurra]

Controlling both field and armature voltage at the same time is not a very good idea. But if you feed the field from a separate rectifier (you can make a small one using four 1N4004 diodes and connect directly to mains (if it is somewhere around 110 V). Then control armature with your PM motor controller. The constant field works exactly like a PM excitation.

Gunnar Englund

http://www.gke.org

 

[richard29e5]

Gunnar
What does the circuit look like with the 4 1N4004 diodes.
And I think you suggest connecting this circuit directly to the incoming 115v ac.
Richard29e5

 

[Skogsgurra]

This link shows a "bread-board" Graetz Bridge

http://www.fpnnysa.com.pl/wersja_an...wrot=1&slowo_szuk=&archiwum_szuk=&gdzie_szuk=

First: Disconnect field windings from armature.
Second: Hook up the diodes as shown. Observe polarity!
Third: Connect the field winding to the + and - terminals.
Fourth: Connect mains 115 V to the free terminals.



Gunnar Englund

http://www.gke.org

 

[Skogsgurra]

Sorry, that link doesn't work very well. Try this;

http://hyperphysics.phy-astr.gsu.edu/hbase/electronic/rectbr.html

Gunnar Englund

http://www.gke.org