Ok, i burnt my brand new 50€ worth MD23 motor controller. I'm deeply desperate... I was all excited about its arrival with all the RD01 kit, i was all happy about the incoming testing and building and having fun with it, when suddendly all the magic smoke came out of it and dispersed for good. :( BWAAAAAA :( i'm so saaaad :(
Sniff, ok.. So i'd like to at least have some idea of what happened, becouse i have none.. How can it happened ? This is the chip that smoked:
what is is ? I was normally feeding the board with 12V for motors (logics use 5V, with internal regulator), i connected the SDA and SCL of the arduino and MD23 together. The only strange thing i did was connecting the ground of the MD23 to the ground of the Arduino. Is it wrong? It wasn’t working without it, and when i connected it worked for some time before smoking out. I did it becouse it was not communicating properly throu i2c, i thougt that maybe it wasn’t able to drain the line or something like that (the lines are pulled up). Did i lost my mind? If i have two board communicating with i2c, each with its own power source, should it be enought to just connect SDA and SCL, or also ground or 5v or anything? Or what else could have gone wrong ?
Ok… thanks everybody… i’m going back to my sorrow…
i’m not bad, but they’re that kind of SMD, soldered without holes, and they’re really small… i could give it a try anyway…
If i can read well the chip is labeled 8DH3LL EZ615. They’re a kind of MOSFET i see, from ST microelectronics. I don’t even know where to find them…
Another thing that came into my mind: i’m using a 12V DC adapter from a scrapped router… When i tested it, it outputted about 14 or 15 V without any load (just plugged). I was told that those extra 3V are normal and that it goes back to 12V when you apply any load… isn’t it true? Maybe when the motors are not running it wasn’t “relaxing”… in the md23 sites they say: “Above 14v and the driver chips may be destroyed”.
Could it be an issue of the wall outlet being AC and Batteries being DC? I would assume the adapter corrects that, but who knows. I would assume it sent too much voltage. I wouldn’t trust a 12 volt adapter to stay under 12 volts. Always use a regulator when you want to ensure power stays under certain threadholds.
You may be able to work with the company you bought it from and see if they will swap it out. Tell them what happened and you may get a replacement. I would assume the adapter supplied > 12 volts and fried it.
That’s more or less true – if an AC adapter is rated at “12v 500ma”, for example, then it will only actually output 12v when the load is pulling that maximum 500ma. If the load is pulling less than the max (as hopefully it usually will), then the adapter will put out more than 12v – the lower the load, the higher the voltage, up to a maximum of about 3-5v above its rated voltage. You should never use an unregulated AC adapter if the output voltage is critical – always pass it through a voltage regulator first, or use a regulated AC adapter.
Also, you mention that the wall outlet is AC, which is true. But the more important thing is the output of your wall wart. There are two kinds of wall warts – some output AC, and some output DC. You have to use the right kind. It will say on the label what the output is. Since the MD23 is designed to run from a 12v battery, it requires DC power, so be sure your wall wart is outputting DC.
Sorry you burned it. Hope you can manage to get it working again. BTW, check out mouser.com or digikey.com to find replacement chips like that MOSFET.
I would also try the store I would also try the store you got it at. I know this sounds like a lost cause, but I’ve sent a few emails tellign the store I fubared the product and they still swapped it out. They can send it back to their supplier as DO Aand get their money back and a happy customer. If the product is less than a month old I would give it a go. Worst case they tell you no and you are in the same position. Just be honest…
Since noone have answered (or I missed the answer). No, it is not wrong to connect GND on the two boards. In fact, you should connect them, so they will have the same reference.
Could you have swapped the + and - from the adapter? I don’t know if it will upset the output drivers, but it is a common mistake that I have made a couple of times.
I see… That’s probably the problem… The adapter i was using has output: DC 12V 1A. There’s no way the md23 was eating 1A, not even with motors running unloaded.
But one thing i don’t understand: it didn’t smoked as soon as i connected it, i used it for several minutes before that, and i also used it the day before… Could it be that it just burned after a while?
Another thing: could it be that i ruined the EMG30 motors too ? It shouldn’t be, becouse i was almost never running them full speed, so they should have never received the full voltage. Also, if they where running at max they should have eaten at lest half and ampere, possibly lowering the voltage to somewhere between 12 and 14V. Am i right ? I couldn’t endure the departure of my beloved motors too…
Anyway thanks you all guys! You’ve been very friendly and consoling.
Ok thanks, i was almost sure it was right to do it… Btw, should i connect +5V of Arduino to +5V of the md23? I don’t think so, i didn’t connected them… But maybe it would be helpful ?
No i double check every time for + and -. I always have red and black cables all around…
No, don’t do that. From what No, don’t do that. From what I read in the docs, the 5V is an output. You use it to power other things, so you only need one power supply. If the Arduino could run on 5V, you coul use it to power the arduino, but if I remember correctly, the Arduino need at least 7V or so.
It was probably barely It was probably barely exceeding the recommended voltage so it took a while to overheat. Plugging it in for a short time will cause it to heat up. If you leave it plugged in too long with too much voltage it will superheat and POOF!
The MD23 is designed to work with a 12v battery. In practical terms, this means the 9v-14v swing of a flat/charging 12v battery is fine. Much below 9v and the under-voltage protection will prevent any drive to the motors. Above 14v and the driver chips may be destroyed - their absolute maximum stress voltage is 18v.
What I would say from the descriptions of the hook-up of this board, is that everything is being driven by an inadequate power supply. A 12V 500 mA power supply certainly won’t over-current anything, but it might undervolt the device as it is trying to drive the FETs and the motor. The board probably won’t draw much itself, but the EMG30 motors have a 2.5 Amp stall, which they attempt to draw at least briefly everytime they start up. Trying to get 2.5 A from a 500 mA supply will drop the voltage down pretty substantially. The gate voltage Vgs of the FET really needs to be up around 10-12 volts to ensure complete turn on. Otherwise, they can operate in a “linear” region, that allows a lot of heat being dissipated in the device, and eventual burn out.
In John_ posts, the power supply is not specified, but stated to limit to 2.5 A, not sure what is happening there. It is interesting that the same FET blew, and I wonder about the trace length from the driver to the FET, and any possible PCB errors. Found the LM5104 driver but can’t see any real probs there. It has an Under Voltage LockOut that should have helped some, but may not have been able to shut down in time. Just a weird problem, and thought I’d throw another possible issue out there. What I would suggest is to have 12 volts worth of fresh charged batteries, rather than any type of power supply for running an h-bridge. Maybe with a fuse or PTC device or some other current monitor if you wanted to be safer.
HI, I just burnt my md23 I think the same way. Wierd thing is I’ve been using it fine for months connected to a power supply (12v), and I had been using it for one day with a battery pack that is only 9.6V. Could this be the reason why it went? Although I don’t see how if the voltages are lower surely there’s less risk??
So something like that just happened to me. Both mnotors were working until I tried to connect a Serial LCD to teh Arduino which seems to be shorted somewhere :S When I connected everything Arduino failed and reboothed while one of the motor controllers of the MD23 didnt work at all… Trying it again later on both stopped working… awsome
Can somebody explain me please which component I need to replace and how do I know if it is that one? cause it doesnt seem to be anything burnt!
