Electrical Engineering ⇒ Topic : Mechanical-differential Counter

Mechanical-differential Counter

Fig.(a) illustrates the use of a mechanical differential whose output gear rotates at a speed equal to the difference of two input gears to which the synchronous and induction motor shafts are connected.A mechanical counter or a low-speed electric or mechanical tachometer p used to record the slip speed directly.This method has a disadvantage in loading the induction motor slightly because of the friction and drag in the gearing of the differential, and it should not be employed with small induction motors for measurement of slip. An electric differential with less effective drag may be employed for small induction motors

                                                            Fig.(a) Mechanical differential counter