Conor:
Bking:
better to put a shunt resistor of 15 ohms which will “lock” current flow to 2 amps and “drown” the test pulse to stop flicker.I was starting to suspect you had half a clue until you posted that complete load of utter ■■■■■■■■.
Yours sincerely, a real electronics engineer and not someone who has managed to copy something from Wikipedia.
Keep wiring the houses love auto electrics are way out of your league.
pete904ni:
nsmith1180:
TV tends to work off either 44 or 48 frames per second, i cant remember which.24
Nope, film is 24 FPS. At least all films but Life of Pi, which was the first film shot completely in 48 FPS. TV is higher than standard, which is why a TV picture looks smoother than a in places.
redboxer850:
Bking:
Ive heardDoesn’t mean that it is true.
I’ve heard that Vosa fine you £10 for every turn of the landing leg handle
Have you seen it in writing
Erm yeah I have, was a note from DHL iirc. It was still a load of crap, but a load of crap that someone in a suit believed.
Bking:
Halogen bulb will not flicker on AC as it uses an incadecent filament which allows current to flow in both directions but as an LED is a diode it only allows the positive part of the wave to excite the electrons while the negative phase will be blocked, in effect the LED is acting as a rectifier to convert AC to DC.Very little heat is produced by LED systems whereas incandescent bulbs turn up to 80% of the energy consumed into infra red wavelengths.Also an incandescent element cannot cool down instantaneously but an LED can instantly stop pushing electrons into higher orbits so they cannot fall back into lower orbit by realeasing a photon of fixed wavelength as soon as the AC signal drops below 5 volts positive.LEDs use quantum shell excitation to produce single wavelength light not resistance heating which produces all of the visible spectrum.If you put a “slave” bulb in the circuit when the slave blows you are back to flickering lights better to put a shunt resistor of 15 ohms which will “lock” current flow to 2 amps and “drown” the test pulse to stop flicker.Mains voltage frequency varies between 58 and 62 hz.And probably a lot of you are going WTF is this tow rag on about.But tell you boys some dumb buggers out there running banks but some bright mothers out there driving and repairing trucks.Bet old Einstien would have loved to be a road boy.
I just love it when folks over-complicate things, for whatever reason.
Nearly 40 years age I was a telecom apprentice and one of the exercises that I, and my year, had to do was build a Wheatstone bridge. All the groups had to use a different capacitor value and the point of this was to show the effect that it had on the smoothing, when measured with an oscilloscope. I haven’t used any of that knowledge, in anger, in over 20 years so I accept that the technology has evolved however the basic electrical laws of physics are still pretty much the same as then.
LED will pass electrical current 1 way, incandescent bulbs can pass electrical current either way.
LED will be either on or off, incandescent bulbs will dim with reduced voltage.
It is my theory, nothing more, that the problems with LED flicker is largely an unintended consequence of the developing technology having to work with existing technology in that the truck manufacturers can not determine what trailers will be pulled by their vehicles.
Given the dependence on a specific voltage requirement the bulb testing technology and the number of connection opportunities that can fail I contend it is an electrical supply problem. With the bulb testing systems could he potential drop below the required level for the LED if applied to the return/earth? likewise the suzies making a poor, high resistance connection which incandescent systems don’t show as readily as LED systems. If the metal on the electrical leads and sockets was bright and tight the connection would be good, certainly better that the loose and tarnished that are a feature of leads which have seen a bit of use (In my own depot 10 pick ups and drops a day per trailer would not be out of the ordinary).
I would finish by noting that the charging of the vehicles batteries is by use of an alternator which generates AC and then uses a rectifier and smoothing technology based on a Wheatstone bridge which, without physically large capacitors, is not constant as it too will fluctuate slightly. That would also, I contend, be why the flicker would be less likely, or apparent, on a physical walk round check or a seat based sensor check if the engine is not running.
Wiretwister:
Bking:
Halogen bulb will not flicker on AC as it uses an incadecent filament which allows current to flow in both directions but as an LED is a diode it only allows the positive part of the wave to excite the electrons while the negative phase will be blocked, in effect the LED is acting as a rectifier to convert AC to DC.Very little heat is produced by LED systems whereas incandescent bulbs turn up to 80% of the energy consumed into infra red wavelengths.Also an incandescent element cannot cool down instantaneously but an LED can instantly stop pushing electrons into higher orbits so they cannot fall back into lower orbit by realeasing a photon of fixed wavelength as soon as the AC signal drops below 5 volts positive.LEDs use quantum shell excitation to produce single wavelength light not resistance heating which produces all of the visible spectrum.If you put a “slave” bulb in the circuit when the slave blows you are back to flickering lights better to put a shunt resistor of 15 ohms which will “lock” current flow to 2 amps and “drown” the test pulse to stop flicker.Mains voltage frequency varies between 58 and 62 hz.And probably a lot of you are going WTF is this tow rag on about.But tell you boys some dumb buggers out there running banks but some bright mothers out there driving and repairing trucks.Bet old Einstien would have loved to be a road boy.
I just love it when folks over-complicate things, for whatever reason.
Nearly 40 years age I was a telecom apprentice and one of the exercises that I, and my year, had to do was build a Wheatstone bridge. All the groups had to use a different capacitor value and the point of this was to show the effect that it had on the smoothing, when measured with an oscilloscope. I haven’t used any of that knowledge, in anger, in over 20 years so I accept that the technology has evolved however the basic electrical laws of physics are still pretty much the same as then.
LED will pass electrical current 1 way, incandescent bulbs can pass electrical current either way.
LED will be either on or off, incandescent bulbs will dim with reduced voltage.
It is my theory, nothing more, that the problems with LED flicker is largely an unintended consequence of the developing technology having to work with existing technology in that the truck manufacturers can not determine what trailers will be pulled by their vehicles.
Given the dependence on a specific voltage requirement the bulb testing technology and the number of connection opportunities that can fail I contend it is an electrical supply problem. With the bulb testing systems could he potential drop below the required level for the LED if applied to the return/earth? likewise the suzies making a poor, high resistance connection which incandescent systems don’t show as readily as LED systems. If the metal on the electrical leads and sockets was bright and tight the connection would be good, certainly better that the loose and tarnished that are a feature of leads which have seen a bit of use (In my own depot 10 pick ups and drops a day per trailer would not be out of the ordinary).
I would finish by noting that the charging of the vehicles batteries is by use of an alternator which generates AC and then uses a rectifier and smoothing technology based on a Wheatstone bridge which, without physically large capacitors, is not constant as it too will fluctuate slightly. That would also, I contend, be why the flicker would be less likely, or apparent, on a physical walk round check or a seat based sensor check if the engine is not running.
1 question why does the flicker disappear when the trailer has the EBS/ABS lead disconnected which carries the can bus test signal and why dont they flicker when connected up to a terberg yard shunter that does not have a can bus ring system so does not use a test pulse?Or is that just a coincidence.
Why do I not have this problem with Renaults, Dafs or the Hired 62 plate Merc that I drove yesterday? Questions questions. 
Maybe the flicker that can be seen is actually the LEDS rapidly switching on and off with the test ‘signal’ rather than anything to do with the ac/dc/voltage/frequency/etc.
Ever noticed that you can’t ‘see’ the strobes of emergency vehicle on TV?
W.
Conor:
Bking:
better to put a shunt resistor of 15 ohms which will “lock” current flow to 2 amps and “drown” the test pulse to stop flicker.I was starting to suspect you had half a clue until you posted that complete load of utter ■■■■■■■■.
Yours sincerely, a real electronics engineer and not someone who has managed to copy something from Wikipedia.
I did wonder when I saw the confident assertion that AC mains is at 58-62 Hz. That might be true in North America (where said Wiki article probably originated) but over here it’s nominally 50 Hz.
Well I was out by one. Standard PAL is 50Hz interlaced effectivly 25fps
