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Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 5:25 pm
by bulleidboy
I have just installed a 3v bus under my street and shops, and have wired the taxi lights and the belisha beacons - they all work - but everything is flashing in sinc. with the belisha beacons. I can give the belisha beacons their own power supply (pain :evil:) - but any ideas why this is happening? I was going to add the street lights and shop lighting to the same supply - may be not! BB

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 5:52 pm
by Walkingthedog
Is the power going through the beacons on its way to everything else?

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 6:10 pm
by bulleidboy
No - that's what I don't understand - the beacons are, and will be, at the end of the line. It's a bit like putting a novelty flashing light bulb into a lamp at home, and the whole house is flashing.

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 7:04 pm
by Rog (RJ)
If the various lights are LEDs this can happen if they don't have resistors fitted. One set of lights (usually red LEDs) rob all the power.

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 7:09 pm
by Brian
If the Beacons are not in series then it reads as though possibly the total load is exceeding the power supplies rating? Try removing the beacons and see if the other lights then stabilise

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 7:31 pm
by bulleidboy
I've disconnected the beacons and every thing is fine. Does this mean the beacons need a separate power supply?

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 8:07 pm
by Steve M
I had a similar issue some years ago - solved by fitting each led with its own resistor. It was in the days when I tried using just one resistor for the whole lot.

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 8:11 pm
by bulleidboy
Does it matter which wire (+/-) the resistors are attached to?

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 9:16 pm
by Steve M
Barry it’s one or the other. :D

Try this:

http://led.linear1.org/led.wiz

Re: Houston - we have a problem!!!!!!!!!

Posted: Sat Oct 17, 2020 9:21 pm
by bulleidboy
Thanks Steve - I think that will be helpful. Barry