a/c motors please help

Wave and lap wound motors for DC motors differ in that a wave wound machine will have 2 parallel current paths- the winding progresses from one commutator bar, through several coil sides, around the armature until it reaches the next commutator bar. In a lap machine, the number of paths = the number of poles. Each coil is connected between adjacent commutator bars. Except for two pole machines, for a given power, the lap wound machine will be a lower voltage,higher current machine than the wave wound machine. N S N S |-------------| |-------------| | | | | Wave goes around machine / |____________| \ Next part of winding from bar2 to bar 3 bar1 Bar2 N S N S |-------------| |--------------| | | | | Lap -next coil from bar 2 to bar 3, etc \ / \ / Bar 1 Bar 2 Bar n Bar n+1

You indicate a/c in the header- do you mean AC? Universal motors are essentially DC series motors which will run on AC. Most AC motors are induction or synchronous machines where the "armature" is stationary and a commutator is not used so "wave" or "lap" really lose their meaning. An AC winding will have a group of coils which are connected in series and may have several such groups in parallel. The coils are distributed to get an (stepwise) approximate sinusoidal distribution to eliminate or reduce harmonics.

-- Don Kelly snipped-for-privacy@peeshaw.ca remove the urine to answer

Don explains this very well. Tim, I recall in my Motors course, I got confused on the lap and wave windings difference also. It helped me to just study the electrical circuit diagram for both windings, rather than trying to picture the actual windings in the pictures that the textbook showed.

Bar

As usual, Don explains this pretty well. I always remembered that in 'lap' windings, the current flow takes several 'laps' around the armature face through several coils to get from the bar under one brush to the bar under the next brush.

daestrom