14-02-2018, 12:10 PM
Good morning. Since my previous reply I have been reflecting (no pun intended) on whether the fitting of main and dip bulbs would achieve the desired outcome. The reflectors fitted to CAV and the later Lucas R510's were not designed to be so used - reflectors with a main/dip function place the main beam filament at the focal point of the parabolic reflector and the dip filament 'offset' so the light beam is reflected downwards. This is why the bulbs in early dipping headlamps had to be 'focused' hence the term 'pre-focused' and inserted the right way up.
My experience of CAV and 510's suggests that they merely direct the light outwards.
Further I have recently been asked why twin contact bulb holders were sometimes fitted to these early lights - the answer seems to be that one contact was live and the other return (earth).
In an earlier posting it was explained that sidelights and headlights are achieved with single filament bulbs by switching the lamps in series to give a 3v output (sidelights) and parallel to give a 6v brighter output (main).
Regards from the creative county - Staffordshire
Stuart
My experience of CAV and 510's suggests that they merely direct the light outwards.
Further I have recently been asked why twin contact bulb holders were sometimes fitted to these early lights - the answer seems to be that one contact was live and the other return (earth).
In an earlier posting it was explained that sidelights and headlights are achieved with single filament bulbs by switching the lamps in series to give a 3v output (sidelights) and parallel to give a 6v brighter output (main).
Regards from the creative county - Staffordshire
Stuart