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LED headlight flickering

I finally got around to fitting a nice bright H4 LED lamp to the B33 and it flickers when the engine is running. Any ideas why and how I can remedy it?
I had a similar problem when I used a Thorsparx on a bike with LED indicators that then flickered all the time - just fitted incandescent bults instead.

cheers

email (option): petercomley@web.de

Re: LED headlight flickering

What voltage regulator are you running? The original Lucas one or a modern solid state type?

Does the bike have a battery?

Re: LED headlight flickering

Sorry, I should have given a bit more info

I have a DVR2 positive earth system. (6V)
Complete rewire with individual earths to headlamp etc.
Battery fitted and fully charged
Lamp is from Paul Goff, LED headlight P43t H4 6V/12V, dual polarity
Magdyno, E3L cleaned and flashed and working well.

:slightly_smiling_face:

email (option): petercomley@web.de

Re: LED headlight flickering

I have the same problem with my M33, fitted with Goff lamps but running with a original Lucas regulator MCR2. I always thought it was the mechanical regulator that caused the flickering but you are running with a DVR, so looks like that rules out the regulators then.

Re: LED headlight flickering

So if you have a battery fitted and it only flickers with the engine running, I would suspect you have a bad wiring connection somewhere and the vibration of the engine is causing the connection to fail. With the old bulbs you won't see it flicker as the filament of the bulb still glows for a time even after the power to it has been lost. Disconnect the generator wires and start the engine, does it still flicker? If so it has nothing to do with the charging system.

My bike has a modern regulator and all LED bulbs. No problems at all.

Without seeing the bike, I am just guessing.

Re: LED headlight flickering

Sometimes they flicker. But mostly only on idle, once the revs get up it is fine. Sometimes, an "anti flicker harness" helps. search on Ebay

email (option): cas.vanderwoude@gmail.com

Re: LED headlight flickering

The "anti flicker harness" is nothing but a capacitor. It is for modern cars and motorcycles that use pulsed current to the bulbs. As an example my 2008 BMW R1200RT motorcycle has only a single filament bulb for the tail light and brake light and it pulses the current when the tail light is on and provides full current when you apply the brakes making to brighter. Hard to believe this is cheaper than using a dual filament bulb, but what do I know? If you replace the incandescent bulbs with a LED it won't like the pulsed current and it will flicker.

Now if your M20 is flickering on LED bulbs it means it is not seeing a steady voltage. At idle the generator is not providing much power at all and the battery takes over. So if your lights are only OK at speeds above idle when the generator takes over, you have a weak battery.

And again, disconnect the generator so the lights are only running off the battery. Turn on the lights and see if they look OK. Then start the bike and if it starts flickering again, you have wiring problems and not the battery or charging system.

Re: LED headlight flickering

latest:

lights OK, no flicker with battery and stopped engine,
lights flicker if the engine is then started with dynamo and regulator functioning.
If I detatch the dynamo then the flickering goes away when the engine is running. Seems to rule out HT interferrence.


Someone suggested the regulator was not "smoothing" out the pulses from the dynamo. I don't think this is it's functon, it just regulates the voltage and dynamo output,
I noticed that the LED rear light/brake light cluster also seems to flicker under the conditions above, although not as badly (more LEDs, not as bright??), never noticed this before as it is usually behind me 😅

I suspect it may be that the dynamo delivers a pulsed charge, which is not an issue with an incandescent bulb, and might be giving a “boost” to the LEDs, which react much more rapidly to voltage changes, so resulting in the flickering.

Anyway I have given up for the moment and reinstalled the original bulb. The LED will be tried out on an alternator/Podtronics 12V system later.

thanks for all your suggestions
Cheers

email (option): petercomley@web.de

Re: LED headlight flickering

I also did what Bruce recommended, bike running with the D&F connected at the dynamo, lights flickering. Disconnect D&F and the flickering stops as i said i always thought this was down to me having an original mechanical regulator, but Pete C has the same proplem with a DVR. Then i noticed that if i rocked the light switch the light flickered also the 2 terminals on the lamp connections on the back of the DU42 reflector caused the lamp to flicker if moved. I cleaned all connections and sprayed the switch rotary plunger connections at the same time as moving the switch. I also checked that i had a direct earth wire from the earth point on the lamp panel back to a common frame earth mount. I now have a steady LED beam that you could use as daytime lights if needed. Problem these lamps are pretty crap in the dak as you dont get a beam it's just a wide light.

Re: LED headlight flickering

Not with the latest iterations, they give a beam

email (option): jeremy@clogmaker.co.uk

Re: LED headlight flickering

I run led lamps, DVR reg 12v -ve earth on my M20 with no perceptable flicker.

Re: LED headlight flickering

I is hard to find a good LED globe with a 6 V + ground system
Even if you sawp it to - ground most give a very poor headlight.
Stop / tails are great but headlights are crap
This is because the LED is flat & has a beam spread of 100 to 170 degrees
A tungsten eement has a beam spread of 360 deg
So an single element LED can only use slightly less than 1/2 the reflector
Most of them use 2 high energy LEDs, one for the low and both for the high
It is near impossible to correctly position them in our reflectors so both the H & L are focused properly in the reflector
And beecause each element uses around 1/3 of the reflector you end up with a laying down D shaped low beam and a sort of figure * high beam with dark patches at either sides, good for approaching traffic but not much help if you can not see the edge of the road.
12 V globes are 200% better as most use 2 chips for each beam arranged in a V for the high & inverted V for the low
These give the best light but you get overlap from the chips both sides
Not a problem in OZ but a big one in the UK & EU where they test with a beam setter as the overlap on the on comming side is quite dazzeling
The other options are the multi element acorn style globes with a resistor so you get the same beam spread H & L just more light on H
The third style has a single CREE chip behind a lense I use a blinker x

These tend to gice a pencit type of light that again does not change the beam spread H to L just the intensity
I found these were the only style that gives off enough light to ride faster than a walking pace but do not give a wide enough beam
The solution for me was to put an acorn style globe in the parking holder and wire the bike so it stayed on when I went to H or L
I use a Miller blinker / horn switch to switch from H-P-L and the original switch for off tail only tail + parking & head light .
Not original of course but nothing else is and I ride this bike day or night .
The tail only is good for times if the battery is going flat and the dynamo is not working ( thanks to the sh#! Wassel regulator )

Re: LED headlight flickering

Despite saying above that the M20 led doesn't flicker I noticed flicker on the BSA A10 led headlamp last night which got me thinking about Critical Flicker Fusion. We all vary in our sensitivity to percieving flicker (flicker threshold) as individuals and within ourselves for various reasons (fatigue, region of field of view, or health). For a review see...... https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8537539/.

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