Harmonics is one possible problem, there are others such as voltage spikes from other equipment, induced voltages from adjacent circuits, incorrect voltage due to load variations in the rest of the system and so on.
LED lights failing
- Thread starter Simon35
- Start date
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Metal oxide varistors across the supply would be more usual, to protect the LED module from excessive voltage.
Excess voltage or spikes over an extended period will cause it to fail, and failure modes are either short out the supply in a blackened mess or fail open in which case the LED module will be damaged.
So there is a driver albeit integral to the assembly of LED(s) and heatsink.
More accurate the lamp is direct on line ( as in no power supply module required between line and lamp )
Yes. This is a typical example:
While 'driverless' is not entirely accurate, it's just like many other terms which are used incorrectly all the time.
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Tell me about them.
There are driver less LED lamps. They have two strings of about 80 LED elements and a resistor in series connected directly to the mains supply.One strin conducts on the positive half cycle and the secnd string conducts on the negative half cycles. A slightly better design replaces the resistor with a crude constant current device but that woudld be a driver.
Such a system obviously requires that the LED elements can tolerate the reverse potential during the non-conducting half-cycles. What is the typical maximum reverse voltage of an LED element?
Kind Regards, John
Typically the reverse breakdown voltage is at least 150% of the forward voltage. The conducting string acts as a voltage limiter and ( with a shared resistor ) the reverse voltage across the non conducting string is lower than the total of the EDIT reverse breakdown voltages
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Fair enough. If they work, one has to assume that that is adequate!
[slight typo correction needed there, I think ]
Again, fair enough. Although I imagine that the voltage drop across that common resistor would be fairly small, by definition the total reverse voltage across the non-conducting string would be the same as the total forward voltage across the conducting string - so that, with that 150% 'leeway', that should be fine.
Kind Regards, John
The fittings have failed with nothing else starting or running, either on this equipment or elsewhere in the building so I think I'm ruling out voltage spikes or variations.
I might look at what filtering I can fit after the transformer, and give the transformer supplier a call, might be a problem they have resolved in the past.
Thanks all for the ideas and input, and am pleased it provoked a discussion
Sorry, missed this one on page 1!
Fair enough - so do I take it that there is one transformer, fed from one phase-phase of a 3-phase supply (with
Kind Regards, John
Edit: crucial typo corrected
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Yep, although there is no neutral easily available.
Ah. That's what I actually thought, and that quote was a typo on my part - I intended to write "with no neutral available" (now corrected)!
Kind Regards, John
Thanks for the update.
Whilst you obviously can know that the buzzing has gone, is it not rather premature to be talking about "no failing lights"?
Kind Regards, John
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