@shorling posted:As you have correctly noted this waould be a major design flaw. However this vendor has been successfully selling this product for many years. They are the major supplier of this product which is why you see them at York. It is not like they are a startup and released a new product. I run over 100 of their direct replacements on my layout with zero failures or degradation over many years.. That performance is not possible without addressing reverse voltage in the design.
Without a diode, they did not address a major design shortcoming. They're exceeding the ratings of the LED whenever the applied AC voltage goes over around 5 VAC, if some of the product is not failing, they've just been lucky with the LED's taking the abuse. I don't know if the LED's you are using have the same design, but the item in this thread we're looking at is a defective design, there's no if's, and's or but's about it. Any design that violates the absolute maximum ratings of a component is a bad design, even it it happens to work a majority of the time. This is electrical engineering 100, it doesn't even rate the 101 class!
