lawn mower intermittent fault

[Mr Red]

My electric lawn mower was starting only intermittently so I took it apart to find the fault. The switch and motor work and the 22uF capacitor tests OK. Which leaves the centrifugal switch. I can't for the life of me work out how this centrifugal switch operates in this context. When the motor is off the centrifugal switch comes into contact with the two non conductive pads on the motor housing, when it is running it doesn't but there doesn't appear to be any way to control the circuit in the stator with this setup. Can anyone enlighten me? My pictures show how I think the circuit should operate and the rotor with the centrifugal switch and the non conducting pads highlighted. TP1,2 and 3 in the circuit diagram are the locations of the wires that come out of the motor.

mower circuit.jpg (108.26 KiB) Viewed 875 times

mower motor.jpg (214.39 KiB) Viewed 875 times

[ericmark]

A centrifugal switch normally disconnects one winding once motor is running, but there are so many ways of starting a single phase motor one could write a book on them.