vikas_5891
Newbie level 4
Dear Sir/Madam,
I have problem in speed control of DC shunt motor chopper circuit. My motor is working fine when i connect it in open loop configuration by varying the armature voltage (armature voltage is varied by varying duty cycle) but when i connect the motor in closed loop system, the speed of motor suddenly increases automatically (armature voltage increases from 0-120V automatically ) and my chopper circuit gets bypassed and motors starts to operate in free running mode. i am attaching my circuit with this post. Can anyone please suggest me the way out for my problem...
![](https://obrazki.elektroda.pl/21_1337408228_thumb.jpg)
I have problem in speed control of DC shunt motor chopper circuit. My motor is working fine when i connect it in open loop configuration by varying the armature voltage (armature voltage is varied by varying duty cycle) but when i connect the motor in closed loop system, the speed of motor suddenly increases automatically (armature voltage increases from 0-120V automatically ) and my chopper circuit gets bypassed and motors starts to operate in free running mode. i am attaching my circuit with this post. Can anyone please suggest me the way out for my problem...
![](https://obrazki.elektroda.pl/25_1337408228_thumb.jpg)
![](https://obrazki.elektroda.pl/21_1337408228_thumb.jpg)