L.E.D. Driver Failure ?

[colin H]

I recently fitted 6 L.E.D. wedge lights under my kitchen cabinets , connected to the lighting circuit . Bought from B+Q . I have 4 fitted on one driver and 2 connected to another . This is the driver I have .

http://www.ebay.co.uk/itm/Sensio-LE...ighting_Lamps_Lighting_SM&hash=item2a12130fdc

Everything worked fine for a month or so , but now , the driver with the 4 lights has failed . I swapped everything round , and the lights are fine ,no loose connections within the circuit ect , so Ive isolated the fault to the driver . The lights are rated at 1.4W each , and the driver is 15W

Is there a reason why the driver would fail ?

 

[ericmark]

Something seems wrong 15W at 12 V when I went to school = 1.25 A not 6 A.

Theory as you rightly say means you should be able to run 5.6W total devices from a 15W supply but the picture is not good enough to read what it says.

Inverters use a mark / space relationship to get the correct voltage and often there is a minimum mark time. In layman's terms this means there is a minimum and well as maximum output. It states "long time open circuit protection" which makes me think there is a minimum value and I wonder if it has been under-loaded?

I would not think there is anything wrong with what you have done and likely it is just a case of the unit failing and needing replacement however since I can't read the details makes sense to ask the minimum ratting of the unit.

 

[colin H]

Thanks for that ! I`ll take the unit back to the shop , and see if they`ll replace it

 

[aptsys]

Inverters use a mark / space relationship to get the correct voltage and often there is a minimum mark time. In layman's terms this means there is a minimum and well as maximum output. It states "long time open circuit protection" which makes me think there is a minimum value and I wonder if it has been under-loaded?

It shouldn't be a problem for step down switchers as they should be allowed to enter discontinuous conduction mode. The failure is more likely to be due to it being a cheap driver.
Inverters can be easily damaged by open circuit as you say since it is easy to destroy the output transistor(s) from the high voltages from the inductor if they have skimped on the design, but this isn't an inverter, so not a problem.

 

[colin H]

Thanks chaps !

Is there a way of guarding against it happening again ? Like I said earlier , I`ll try and get the shop to give me a replacement , but for future reference , is there a better quality driver you could reccommend ?
Also , would it help to split the four lights into two pairs , and add an extra driver ?

 

[colin H]

just an update on this thread .

I replaced the driver , and it failed again after a week . I`ve since replaced it again AND added a third to the circuit , so I now have 2 lights running off each driver .

Everything has now worked fine for the last 3 months , so I`m guessing 4 lights must have been too much !

 

[Monkeh]

Something seems wrong 15W at 12 V when I went to school = 1.25 A not 6 A.

I think they're referring to the fact that 6 AMP Micro MATE-N-LOK connections are available.

 

[ban-all-sheds]

Is there a reason why the driver would fail ?

Yes:

Bought from B+Q .