GU 5.3 12V LED - AC/DC rating query

[YorkshireMidge]

Looking to swap a halogen 12V GU 5.3 for an LED in a relative's fibre optic Christmas tree - but when I look around, I see bulbs saying they are for 12V DC, ones that say 12V AC, ones that say they will work on either, and ones that don't say anything other than 12V.

Confusing, so I assume there is a story/history to this? They don't have a polarity - so the LEDs must all have some rectification in them. The supply in this case is 12V AC off a wall-wart and can't be changed as it powers a 12V synchronous motor too.

I'm trying to find a quality/branded 2W which cuts the choice down considerably - or I'd simply have gone with one that made it clear it was suitable for AC.

Thanks.

 

[333rocky333]

Most I think would work on AC, how else would you know which way round to plug it in

 

[flameport]

They are all AC, as if they were not, plenty would not work when plugged in the wrong way or be damaged etc.

 

[YorkshireMidge]

They are all AC, as if they were not, plenty would not work when plugged in the wrong way or be damaged etc.

Most I think would work on AC, how else would you know which way round to plug it in

It would make sense if that was the case. I've just found an old spare low voltage halogen driver unit that is 12V AC output - so you'd expect anyone making an LED bulb in the same format would make them directly interchangeable.

I've also just checked an LED driver unit I have in use for worktop lights in the kitchen and that is 12V DC output, into those little G4 LED capsule bulbs which are just two pin/no polarity too. Those bulbs are clearly stated as working on 12V AC or DC, so I don't see why some manufacturers make it equally clear - and some don't.

 

[ericmark]

Once I get to my PC I will find a link, but for narrow boats and the like 10 to 30 volt DC are sold, I suspect a switch mode power supply inside, so needs smooth DC.

 

[ericmark]

https://bedazzledledlighting.co.uk/ is the link, note these will likely be damaged if connected to an AC supply.

Before LED the quartz halogen lamps for boats and caravans were also different to household types, as in the main we expect to see between 11.8 to 14.8 volt on a battery systems, but near enough bang on 12 volt from a mains system.

I note many household bulbs are marked 50 Hz, likely they will work on AC and DC, however it depends on what is used as a driver, if a capacitor is used, then it would need to be 50 Hz. I suspect reason for 50 Hz is to show not suitable for a kHz switch mode power supply. One as the load may not be enough, and two as it could become a transmitter. But that is only a guess.