I'd say it's a very good idea that you stick to the mechanical commutation.
Hi Polyrhhythm That is a very interesting observation, and it aligns with what I am seeing in practice. At this stage, I am deliberately staying with the mechanical commutator, even though I understand the advantages of solid-state switching. My goal is to first understand the behaviour of the system in its original form before attempting any modernisation. Your comment about the mechanical contacts doing something that solid-state switching could not replicate is particularly relevant. I suspect that the commutator is not only switching current, but also introducing a natural form of overlap, transient behaviour, and possibly beneficial irregularities that are difficult to reproduce with clean electronic switching. In my case, I am working with laminated cores (35SW250) with pole shoes, and I have been focusing on achieving consistent magnetic coupling and repeatable results in the air gap. The core geometry and material selection were done specifically to minimise losses and improve the response of the magnetic field at the relatively low operating frequency (around 25–50 Hz). I have also implemented primary coils with multiple taps (approximately 74, 150, and 240 turns), and I have observed that each configuration requires different resistor values to achieve suitable current shaping. In earlier tests with fixed resistors, I had to find a “sweet spot” by adjusting the commutator speed, which suggests that the interaction between inductance, resistance, and segment timing is critical. This reinforces the idea that the system behaviour is strongly dependent on timing and transient effects, which may explain why a straightforward solid-state replacement does not always produce the same results, even if the waveforms appear similar on the oscilloscope. For now, I will continue with the mechanical approach and focus on obtaining reliable measurements before attempting any transition to electronic switching. Regards, Lasco
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Practical experimenter interested in electromagnetic systems and induction, focusing on measurement, repeatability, and careful evaluation of historical concepts.
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Topic: Clemente Figuera revisited (Read 30886 times)
