Question about a Mars hack/DIY to Strips build.

Kenny Grows

Active Member
@Randomblame Sorry to just at you like this. But you have been very helpfully and i'm hoping you can clear something up for me. I only have one light built so far and i plugged it into my wall Watt reader, I feel like it's pulling weird numbers. It says 125V and .426mA, 52W total from just one driver. I thought each driver should pull 55-75V. I've uploaded pics of the different readings and a pic of my wiring just incase i wired it wrong.
 

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Randomblame

Well-Known Member
@Randomblame Sorry to just at you like this. But you have been very helpfully and i'm hoping you can clear something up for me. I only have one light built so far and i plugged it into my wall Watt reader, I feel like it's pulling weird numbers. It says 125V and .426mA, 52W total from just one driver. I thought each driver should pull 55-75V. I've uploaded pics of the different readings and a pic of my wiring just incase i wired it wrong.

Nono, it's all good, mate!
A watt meter measures only the consumption in AC at the wall.
The driver converts the AC input voltage(in this case 125vac) into a DC output voltage(here 55-75vdc with constant current).
52w converted from 125vac/0,426mA will be 75vdc and ~600mA + a conversion loss of a few percent.
AC to DC conversion is always associated with a certain conversion loss.
The best Meanwells are 96% efficient, so in the best case only 4% is converted into heat. The cheapest e3ay/china drivers are 78-85% efficient, which means up-to 22% is converted into heat. Therefore, drivers also need some cooling and you can improve their life and efficiency when you're cooling them.
With a simple multimeter (e3ay, <10 $) you can measure the DC output voltage and current. Wall-Watt-Meter like Kill-A-Watt or yours only measure the AC input voltage and current at the wall!

Your driver is probably 86,5% efficient, he delivers 75vdc and 600mA constant current. Thats 45w net. + around 7w(13,5%} of heat= 52w at the wall and that means it works exactly as it should.
 

Kenny Grows

Active Member
Thank you for clearing that up. I was thinking it had something to do with the AC side. I plug in a few fans and a charger after my last post they all had 125vac. I will hang up my new light immediately. Thanks again
 

Randomblame

Well-Known Member
Thank you for clearing that up. I was thinking it had something to do with the AC side. I plug in a few fans and a charger after my last post they all had 125vac. I will hang up my new light immediately. Thanks again
All yours electronic devices use 125VAC from TV to PC to the fridge, even your small 5v/1A usb mobile charger use 125VAC. In my country you can also take 220-240v, which is useful for LED drivers(even better effiency) but in your country all wall plugs delivering 125VAC. Therefor each device has it's own power supply.
 
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