Welcome to the Austin Seven Friends web site and forum

As announced earlier, this forum with it's respective web address will go offline within the next days!
Please follow the link to our new forum

http://www.austinsevenfriends.co.uk/forum

and make sure, you readjust your link button to the new address!

Welcome Austin seven Friends
This Forum is Locked
Author
Comment
View Entire Thread
Re: Flickering LED lamps

I have used the combined Tail and Stop LEDs from Dynamo and Regulator conversions. Those supplied to me used a simple series dropper resistor to allow a 3 volt (approximately) LED to be used on 6 volts. Clearly, if the supply voltage varies as the engine revs change, the current through the LED will also vary a bit and some change in brightness will be seen.

One other thing to be aware of is that these particular LED conversions actually had just a single LED, with two different values of dropper resistor joined together at the LED live end. Thus the LED current (and brightness) will be large or small depending on which pin and resistor is being energised. Most of the time this will work as intended, however there is the opportunity for unwanted back feeding, depending on what else is connected to the side and brake circuits.

In my case I had a third central brake light with an ordinary bulb. This was back fed from the LEDs and robbed the sidelight circuit when the brakes were off, leading to no sidelights. I had to solve this problem by adding series diodes to prevent the back feeding before things would work properly. This only came about after a great deal of investigative work and head scratching which I could have done without !

Location: New Forest