5 YNCHRONIZA TION S YSTEM 



471 



Three slip rings are provided at points 120 electrical degrees apart 



for furnishing three phase power to supply plate and filament 



voltage for the regulating circuit. 

 A pilot generator of the inductor type is built into the motor frame 



and delivers a frequency proportional to the motor speed for 



actuating the control circuit. 



Fig. 1 — New television motor and vacuum tube control circuit. 



5. A hydraulically damped coupling is provided between the motor 

 shaft and the scanning disc. (Fig. 4.) 



The motor frame was made from a standard 36 tooth stator punching 

 by cutting out three teeth per pole, thus forming four polar areas of 

 six teeth each. The shunt, series and regulating fields enclose the 

 31 



