Page 51 - Industrial Power Engineering and Applications Handbook

1/32 Industrial Power Engineering and Applications Handbook

Rotating
Static armature
series field .
0 m

* Vr(a.c. or d.c.)
(a) Schematic diagram

Positive half cycle'
I I
1/ No-load ,feed I I i
'-G

I
I
Time -
I

Negative half cycle
Torque (T) -
0 Tr Negative half cycle

T,, I, and N, are the rated values * ax. 1-@
or d.c.
(c) Pulsating torque
(d) Characteristics of a universal motor (b) Theory of operation on 1-0 a.c. supply
Figure 1.27 Theory of operation of a universal motor