Universal Motors: Overview
| 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 |  |
