Split-ring commutator

If the slip rings of the elementary dynamo are replaced by a split-ring commutator, then a DC emf and current will be generated as shown in Figure 2-71. If the single... 

Figure 10.9. Schematic to illustrate principle of split ring commutator for rectifying AC to DC.

If the slip rings of Fig. 4.5 are replaced by a single split ring, called a commutator, the generated emf will be seen to be in one direction, as shown in Fig. 4.6. The action of the commutator is to reverse the generated emf every half-cycle, rather like an automatic change-over switch. However,... 

To reverse the direction of the current, the ends of the armature wire are connected to different halves of a split ring called a 30 commutator. Current flows to and from the commutator through small carbon blocks called brushes. As the armature turns, first one half of the commutator comes into contact with the brush delivering the current, and then the other, so the direction of the current keeps being reversed. 

A simple dc motor consists of a field magnet and an armature. The armature is placed between the poles of the magnet. The armature is made up of a loop of wire and a split ring known as a commutator. The loop is comiected to the commutator. Current is supplied to the motor through carbon blocks called brushes. 

In order to validate the commutability of the DGKC control materials it was necessary to perform split sample measurements with patient samples using the test kit in parallel to the IDMS reference procedure for progesterone. The investigation revealed for both the patient sera and the ring trial results a considerable bias in relation to the reference procedure at low progesterone concentrations. (Fig. 7). The reason for the bad performance of the test was obviously a lack of specificity rather than a lack of commutability of the control materials. At even lower progesterone concentrations the bias increased up to 1000%. It should be noted that the kit manufacturer did unfortunately not issue any lower limit of determination for his measurement procedure. 

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