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Main => General Discussion Board. => Topic started by: kurt-olsson on July 21, 2016, 09:29:47 AM

Title: New driver for backlight
Post by: kurt-olsson on July 21, 2016, 09:29:47 AM
My MCP draws 2.4A, my EFIS draws 1.2A and i have two. I use real bulbs so i get pretty high draws (0,06a per bulb)

My powersupply can output 30amps max, but i will not load it more than 20 so it dont overheat.

But i need a pwm driver that can handle high powerdraw so i can use one for the overhead, one for Mip and one for pedestal like the real plane.

I found this! 50A!!! Looks like it can handle alot of heat!

What do you Think?

http://m.ebay.com/itm/Latest-IBT-3-DC-50A-5V-15V-Stepper-Motor-Driver-Module-H-Bridge-Double-PWM-/131631154148?nav=SEARCH (http://m.ebay.com/itm/Latest-IBT-3-DC-50A-5V-15V-Stepper-Motor-Driver-Module-H-Bridge-Double-PWM-/131631154148?nav=SEARCH)
Title: Re: New driver for backlight
Post by: KyleH on July 21, 2016, 11:16:59 AM
Quote from: kurt-olsson on July 21, 2016, 09:29:47 AM
...

I found this! 50A!!! Looks like it can handle alot of heat!

What do you Think?
...

Does it?

Lets do a bit of math  ;)

I'll be generous and use best case scenario

5V at 50A is 250W. Lets say it's 95% efficient, 250W x 0.05 = 12.5W of power lost in the driver. Does that heatsink look like it can handle 12W of power?

For reference, here is a 250W LED driver:
http://www.lumastream.com/products/intelligent-multi-channel-led-driver-dimmers-226-240-watts/trinity-12-dmx (http://www.lumastream.com/products/intelligent-multi-channel-led-driver-dimmers-226-240-watts/trinity-12-dmx)
Now, this driver include the power supply and drivers, so I expect it to be much less efficient than the one piece.

Take a look at the other products they have in that e-bay listing. Anything with significant current has a much larger heatsink than that board does.

Now I may be wrong and maybe they used expensive MOSFET's or IGBT's to build it and it is ultra efficient, but always have your guard up when looking at things like this from China.

It may be fine in your application, but just be cautious.
Title: Re: New driver for backlight
Post by: kurt-olsson on July 21, 2016, 01:06:03 PM
Hm... I guess your right. Better to use multiple drivers and smaller current. That is probably safer and a better solution.

Thanks for your input.