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I have a 3-CH DMX controller (5-24V, 5A/ch, common anode) from amazon (don't know if links are desired here) and a 12V 100W MCPCB LED panel, which unfortunately has a common cathode. The panel is equipped with 200pcs 3.0V 0.5W LEDs and has two different LED types (bi-color). So I would connect to the panel with two channels from the controller to change the brightness for each channel of the panel. Because of the common cathode wiring of the LED panel both channels are up, when changing brightness on either channel.

I would like to modify the DMX controller outputs so that it can handle this panel. Can you recommend which MOSFETs I should use and how I wire them? Or another solution that is suitable for this project. Per channel I have 4.16A in the line.

Thanks a lot!

Edit: I'm attaching an image and pinout of the controller (for the led panel board i don't have schematics, but the manufacturer confirmed that this panel has common cathode wiring):

enter image description here

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  • \$\begingroup\$ "... don't know if links are desired here ...". No, they're required here so we know what you are talking about, but please don't link to an Amazon catalog page, link to the datasheet which gives pinout and specifications. "No datasheet? No sale!" Welcome to EE.SE. \$\endgroup\$ – Transistor Dec 6 '18 at 18:22
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You'll need to connect a MOSFET in this way for every output in your driver. This means that a lot of transistors are needed!:

Circuit

I could recommend you to buy the correct driver for the LED panel, because for you to implement this circuit, a MOSFET with high current capacity is needed. A TO-220 package (not so expensive) won't stand more than 2W in most cases, and because in a MOSFET, RDS(on) has a positive temperature coefficient, so the warmer it gets, the higher the resistance and gets even hotter, and if you add them a dissipator, the price for this gets even higher.

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  • \$\begingroup\$ Thank you for your answer! I mentioned that the driver and panel both need 12V source, you have 24V in your schematics. Yes, that would be better to buy the correct driver with common cathode but I can‘t find such drivers with >4A outputs on the market... Yes, I understand that i produce heat that way with mosfets but my question is whether and how it is possible to do it because there aren‘t other options for a driver on the market. \$\endgroup\$ – user3729583 Dec 7 '18 at 5:08
  • \$\begingroup\$ What do you mean by „This means that a lot of transistors are needed!“? I have 2 outputs of the driver in use. Thank you in advance. \$\endgroup\$ – user3729583 Dec 7 '18 at 5:40
  • \$\begingroup\$ You will need a MOSFET for each output in your driver, if you only use two outputs, then it´s fine. \$\endgroup\$ – Nightmerker Dec 7 '18 at 15:19

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