MR16 Help Smoke (PROBLEM SOLVED)

[mmais68569]

Why do I keep burning out Mosfets on my MR16?
I am connecting + to + on ch 1 then the red to ch1, green to ch 2, blue to ch 3, running on 12V here is a link to the Flex Strip I am using;

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I am using the full 5M during the test. Using CAT5 from the MR16 to the flex strip first time red came on then green & when it went to Blue Next time when Red came on same thing.
I want to add dumb RGB to my show next year & use the 3 MR16 I have but need to solve this problem first.

          Thanks Mike

[chrisatpsu]

a full strip uses 5A@12v
what are you using as a powere source?

[chrisatpsu]

from the manual

Make sure to only feed the board from a regulated 12 volt DC power supply. Make sure the supply has the current capacity to handle the lights you are controlling. I am using Wirekats 32 led MR16 and they draw about .17 amps per lamp. Plan accordingly to your use.
 

Do not attempt to control more than 2.5 amps per channel from the MR16 controller. This is about 15 of the MR16s I am using per channel. I also recommend you keep the total controller current under 35 amps if possible.
 

[mmais68569]

a full strip uses 5A@12v
what are you using as a powere source?

Here is the power supply I am using.

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Here is also how I wired the CAT5 from the controller to the Flex Strip this maybe the problem?
Ch1 Red connected to the Orange Solid
Ch2 Green connected to the Blue Solid         These were all connected to the Grd side of the controller
Ch3 Blue connected to the Brown Solid
Then
Channel 1       Cat5 Orange Strip, Green Strip, Brown Strip twisted together & connected to the Pos side of the controller
Then connected the other end to the Flex strip with
Orange Solid to Red
Blue solid to Green
Brown Solid to Blue
        and
Orange strip, Green strip, Brown strip twisted together and connected to the white (+side of the strip)



  Mike

[rm357]

If you want to pull that much current through a MOSFET, you need to add some kind of heat sink. I bet that it is getting hot enough to burn you if you touch it...

RM

[mmais68569]

How or what kind of heat sink would you recommend. Yes they are probably getting hot part of one looks to have burned up but I thought that was when it smoked.

            Mike

[RJ]

Why do I keep burning out Mosfets on my MR16?
I

I would say since the manual states:

Do not attempt to control more than 2.5 amps per channel from the MR16 controller. This is about 15 of the MR16s I am using per channel. I also recommend you keep the total controller current under 35 amps if possible.

that it could be because you are pulling twice what the device is designed for from it.  The users are correct you could maybe get away with a heatsink but then you still must consider the traces on the pcb and the other issues.

RJ

[rmp2917]

The specs say that the power supply is 5A @ 12V. It does not say that the strips are pulling 5A.

Even if you assume that they are using the full 5A, it works out to about 1.67A per channel. That is well under the 2.5A recommended. So, I don't see how this would be a problem unless you were connecting more than one strip.

It sounds more likely that something is not wired correctly or that something is getting shorted.

[mmais68569]

RJ

      Here is what it stated on the site

"-Input volts: DC 12V (12V 5A for 5meters 5050 150LED light strip)"

Which I would say is 1.66 amps per channel. Or does it mean each CH is 5amps?
Correct me if I am wrong if it is the second yes that is what is causing then to burn out

             Mike

[jess_her]

Yes I agree with rmp2917.  The way I see it you have 3 channels of 150 LED's each for a total of 450 LED's. IF it is powered with a 5A 12V power supply then it would be at or less than 1.67A per channel.

What my question to Mike is,
How much current can your cat5 individual conductors handle?
Length verses conductor size plays into this.
how much cat 5 wire for lead into your strip is there?
Is the cat 5 and/or  LED strip coiled when burned out?
Need to uncoil them, heat versus resistance thing.

I think your having problems with your cat 5.
Now Cat 5 (stranded conductor) is used on smart strings but it's 128 X 3 max for a total of 384 LED's and are not a 5050 LED ( less current per LED)
Does the flex strip have current limiting resistors?


Think I would find some 18 Ga  stranded wire hookup a strip turn a channel on and watch the MOSFET for a overheat condition. I'll bet it would  work fine if not then cut back on the flex strip until the MOSFET is happy.
Warm to the touch is OK not burning.

[caretaker]

First thing I would do is get a Voltmeter that can read up to 10 amps DC then find out what each channel of the strip is really pulling depending on the LED's the power consumption I saw on one 5050 RGB spec was 30 milliamp s for the Green/Blue x 150 = 4.5 amps! Even at 20 milliamp s your talking 3 amps.   If your readings are under the 2.5 amp per channel I would suggest using a heavier duty cord to supply power to your strips such as a 14 gauge 4 wire trailer wire or similar, the more resistance you add to the circuit the more amperage your will draw.

[RJ]

If that is the case and you are saying 5amp for three channels then it is something wired wrong or a short in the string. I tested mr 16 at 4 amps and while I would not run them this way they did not smoke any of the mosfets.

RJ

[mmais68569]

I think it is also in the wiring & tomorrow I will get some 18ga wire & test them that way.

               Mike
 

[mmais68569]

I rewired the controller & flex strip using a 20ga wire & had no problems. So the problem must have been the way the CAT 5 cable was wired. I ran the program for 30 min. & the mofets did not even get warm.
So now on to the next step ordering from Ray & getting my roof lights changed over.

Thanks for everyone's help & especially RJ for such great products & a wonderful message board to solve problems.

                Mike