02-04-2019, 09:43 AM
Ideally the number of turns times the new current should be no less than the original current times original turns.
And ideally for 12v the armature should be rewound with thinner wire and more turns but that further reduces the total current carrying ability (although at 12v not a great loss.) Some old books on rewinding car dynamos suggest a gauge thicker and I suspect this with some Sevens. Then more resistant to burning out but output reduced even on 6v.
I gather some locals here have rewound their own field coils.
(The weakness with Sevens is the armature. The heating effect is proportional to the amps squared, bearing in mind that includes amps to supply the field and which do not appear on the ammeter. Hence minimising field current is desirable)
If anyone has run 6v with an electromechanical volt regulator and retained 3rd brush would be interested in outcome
If the 12v regulator was designed for a 6 ohm field would expect it to reasonably cope at 4 ohm. it is the guys who claim to run 12v two wire with an e.m regulator and original 1.5 ohm field who mystify me!
And ideally for 12v the armature should be rewound with thinner wire and more turns but that further reduces the total current carrying ability (although at 12v not a great loss.) Some old books on rewinding car dynamos suggest a gauge thicker and I suspect this with some Sevens. Then more resistant to burning out but output reduced even on 6v.
I gather some locals here have rewound their own field coils.
(The weakness with Sevens is the armature. The heating effect is proportional to the amps squared, bearing in mind that includes amps to supply the field and which do not appear on the ammeter. Hence minimising field current is desirable)
If anyone has run 6v with an electromechanical volt regulator and retained 3rd brush would be interested in outcome
If the 12v regulator was designed for a 6 ohm field would expect it to reasonably cope at 4 ohm. it is the guys who claim to run 12v two wire with an e.m regulator and original 1.5 ohm field who mystify me!