30-03-2019, 08:42 PM
(This post was last modified: 30-03-2019, 08:54 PM by Bob Culver.)
The light comes on when the contact opens. some reverse current is necessary to trigger that , ie volts somewhat below battery. usually only ocurs at very slow idle . Even then the light responds only to difference in dyn and battery volts and will only just glimmer . When or if dynamo stops producing competely glows bright.
The reverse current is not easy to read on the ammeter as it is additional to the coil current.
When switch off, after cutout opens, the stilll spinning dynamo feeds the light which is earthed via the ign coil so the lamp responds to difference between dyn and earh and the lamp is quite bright for a jiffy whilst the dyn is spinning.
If light reluctant to go out suggest low dyn output, but then would expect noticeable lamp at very slow idle?
The reverse current is not easy to read on the ammeter as it is additional to the coil current.
When switch off, after cutout opens, the stilll spinning dynamo feeds the light which is earthed via the ign coil so the lamp responds to difference between dyn and earh and the lamp is quite bright for a jiffy whilst the dyn is spinning.
If light reluctant to go out suggest low dyn output, but then would expect noticeable lamp at very slow idle?