29-10-2023, 04:43 PM
(This post was last modified: 24-04-2024, 02:59 PM by Tony Griffiths.)
(29-10-2023, 02:01 PM)David Stepney Wrote: Tony. Why a separate 12-volt battery? A 6-volt system running from the car’s electrical system has worked fine for me over the last five years. I am a great believer in keeping things simple.
I agree, keep it simple whenever possible. But, why 12-volts? Because of all the problems outlined in my previous post. LEDs need a perfect-as-possible earth and often refuse to work due to interference from the engine and stop lights, etc. Standard bulbs on 6 volts are often not bright enough to be seen in bright sunlight. Of course, some 6-volt systems running LEDs do work without problems - I have one car like that, and its 5-watt LEDS have been measured as bright as the 12-volt, 21-watt units on another car.
Instead of a 12-volt battery, to get 12-volt brightness you could use a 6 to a 12-volt step-up transformer, like this (or search eBay for "WaterProof 6V to 12V 3A 36W Step Up DC/DC Power Converter Regulator UK) but, the unit is limited to an output of 3 amps, and, as two 21-watt bulbs draw 3.5 amps it's probably on the margin of not working or, if it does, might fail prematurely? Of course, if the car is "LED proof" it would work with LED bulbs.
Indicators on an A7 can be a problem with no off-the-shelf solution - so I've summed it up as far as possible here: http://www.lathes.co.uk/austin-7-indicators
No doubt I've omitted something, so comments, contributions and corrections are most welcome.