Design Considerations

Synchronous Motors

Power supply	AC
Driver electronics need	No
Speed accuracy	High	Not effected by load torque No closed loop speed control need
Speed control	No	Not possible Speed fixed by mains supply frequency
Position control	No	Not possible — only by limit switches
Overloadablity / load inertia	Low	High start torque or peak load torque Able to accelerate high load inertia
Lifetime	High	Only little reserve for peak load torque Can’t accelerate high inertia
Speed range [rpm]	250...36000	Limited by bearings Depends on lateral force
Efficiency	15...45%	Depend on pole number and mains frequency
Power vs. size	Low	Higher for 2-pole motor
Winding thermal protection	No need	Inductance protected (if winding designed for 100% duty cycle)
Load sensing	Difficult	Load has little impact on current
Stalling permissible	Yes	If winding designed for continuous duty cycle
Electromag.interference EMI	Not Critical	No brushes
Braking/Holding torque	Low	Detent torque (when power switched off)
Max.output power from JE [W]	14	Approximately, for short time duty cycle S2
Linear motors from JE	Yes

Shaded Pole Motors

Power supply	AC	Mains supply
Driver electronics need	No
Speed accuracy	Low	Effected by load torque Speed at rated point about 2600 rpm at 50Hz
Speed control	No
Position control	No
Overloadablity / load inertia	Low	Little reserve to max .torque
Lifetime	High	Limited by bearings Depends on lateral force
Speed range [rpm]	2600	Rated speed at 50Hz
Efficiency	20%	At rated point (14% at ½ rated point)
Power vs. size	Low
Winding thermal protection	Possibly
Load sensing	Medium	Current rises with load, but less than DC mot
Stalling permissible	Yes
Electromag.interference EMI	Not Critical
Braking/Holding torque	Very Low	No permanent magnets
Max.output power from JE [W]
Linear motors from JE	No