Author Topic: lucas dynamo  (Read 462 times)

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Offline Laurie

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lucas dynamo
« on: 28 Mar 2023 at 10:56 »
Just refurbished E3M. New field coil and armature. Polarised correctly and motors smoothly in right direction. But no output when fun by  my lathe. I recall seeing the fix for this but I can't remember. Do I have to swap the field coil connections or the brushes?.  I seem to remember the brush swap changes direction?   

Offline Red

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Re: lucas dynamo
« Reply #1 on: 28 Mar 2023 at 14:12 »
I don't have the answer but the attached may help?

Roy



Image added - Dave, 29Mar2023
« Last Edit: 28 Mar 2023 at 19:39 by Dave »

Offline Laurie

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Re: lucas dynamo
« Reply #2 on: 29 Mar 2023 at 18:08 »
Thanks. A dim memory  came to me today! Reversing field coil connection reverses rotation BUT if the field coil block has no residual magnetism, a perfectly restored dynamo will not produce electricity unless the field coil is energised at start-up of the test run - in the lathe for example. Once running it will self energise and generate electricity. Stop the test, remove battery and restart - there will be enough residual magnetism to self energise the dynamo.