This is quite specific but i don't know another site to ask this on.


I have a driver that has 3 settings, off, dim and full. The lights turn on and work on dim but on full they flash.

Light specifications:

24V dimmable, constant voltage. The lights flash when at full 5m length and when cut down to 1.5m. https://www.amazon.co.uk/gp/product/B018UHCEZ8/ref=oh_aui_detailpage_o03_s00?ie=UTF8&psc=1

Driver specifications:

24VDC, 0~1.25A, [30W max] edit: 10w max (https://d2ydh70d4b5xgv.cloudfront.net/images/a/1/brand-new-ikea-ansluta-electronic-transformer-white-24v-led-power-sup-502-883-39-dc26b7becc947853aea78ec4ebc8c408.jpg) this is not the same as my specs

Any help would be appreciated.

Edit: I apologise i made a mistake, the specs on the driver is 10w max

  • 1
    \$\begingroup\$ Expanding the LED string's specifications, it says they take 40W. You're using a 30W supply... \$\endgroup\$ – 1N4007 Aug 23 '17 at 21:57
  • 3
    \$\begingroup\$ Sounds like hiccup mode over current protection circuit kicking in \$\endgroup\$ – vicatcu Aug 23 '17 at 22:12
  • \$\begingroup\$ @1n4007 that is the maximum wattage. As I understand the specs it is 9.5 w per m. I have tried it at 5m and 1.5m making the wattage about 15w. Am I understanding that correctly? \$\endgroup\$ – rubie Aug 24 '17 at 16:34
  • \$\begingroup\$ @vicatcu how can I prove or disprove this? \$\endgroup\$ – rubie Aug 24 '17 at 16:40
  • \$\begingroup\$ @rubie Ah, I see what you're saying now. I agree with vicatcu that it sounds like the effects of over-current protection. It's not obvious to me why that would be happening if you have indeed cut your string down to 1.5m, since it does indeed seem like that would demand only ~15W. \$\endgroup\$ – 1N4007 Aug 24 '17 at 16:46

The first link to Amazon states in its specifications that the string at full length runs at 40W. And before your edit, you believed it was driven by a 30W LED power supply. The 30W supply would have explained this behavior at the full 5 meter length, but not when cut down to 1.5 meters.

Now that your edit states that it is only a 10W supply (can you explain? the link still shows a picture of a supply with 30W labeled on it), that would explain the behavior at 1.5 meters as well. Between the specs online and your 9.5W/m number, that would still put the power need somewhere between 12-15W.

@vitcatcu put the correct name to this effect - hiccup mode due to overcurrent protection.

  • \$\begingroup\$ The original picture (link) was one i found online and i thought it was the same. It was laziness on my part that led to this. Thanks for the help. \$\endgroup\$ – rubie Sep 5 '17 at 7:27

The flashing sounds like it may be the result of some capacitance that is getting charged and discharged at full voltage. AC transformers have capacitors in them in order to smooth out the waveform (process called rectification). The dim setting might be working at a lower voltage and the power supply struggles to provide the power at full 24VDC. Try measuring the voltage on the power supply, you may have gotten a defective unit.

  • \$\begingroup\$ The standard lights work fine with the power supply but I will attempt to measure the voltage though \$\endgroup\$ – rubie Aug 24 '17 at 16:39

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