Universal Motors: Overview

 

universal motors  universal motors

Power supply AC or DC  Mainly AC, direct connection to mains
Driver electronics need No  
Speed accuracy Low Effected by load torque 
Manufacture tol +-10% of no load speed
Speed control Voltage  ↕ Open loop  speed control
Position control High effort Closed loop position control and sensor need
Overloadablity / load inertia High Very high start torque or peak load torque
Able to accelerate high load inertia
Lifetime Low 300…2000 h  (limited by wear of brushes)
Depends on speed, current and brush config.
Speed range [rpm] 10000…50000 No load speed
Efficiency 60…80%  Operating point of max.efficiency
Power vs. size High
Winding thermal protection Need If overload (mechan.blocking) not excluded -
Current limitation or thermal contacts
Load sensing Easy Current rises with load
Stalling permissible No No or only short time (winding overheat)
Electromag.interference EMI Critical Suppression means (capacitors / varistors)
Braking/Holding torque Low Detent torque (when power switched off)
JE brand Johnson Motor

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