My a4988 burned, what might be the couse?

It had happened on it's own. But before it happened, I connected and disconnected 24V input from the driver several time, while I was uploading code to the arduino and I have seen some little sparks on the pin while connecting it back. Can it be the cause the burning? If so, in what order I should connect and disconnect the driver while I am connecting arduino to pc and disconnecting it.

Usually this can have a couple of causes.

Current set incorrectly (see that little potentiometer).
Incorrectly wired eg. reverse voltage.
No heatsink. Usually a higher voltage and current means you may need one.

Posting tips.

  • Your OS and version can be valuable information, please include it along with extra security you are using.
  • Always list the version of the IDE you are using and the board version if applicable.
  • How to insert an image into your post. ( Thanks Robin2 )
  • Add your sketch where applicable but please use CODE TAGS ( </> )
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Bob.

ballscrewbob:
Usually this can have a couple of causes.

Current set incorrectly (see that little potentiometer).
Incorrectly wired eg. reverse voltage.
No heatsink. Usually a higher voltage and current means you may need one.

Posting tips.

  • Your OS and version can be valuable information, please include it along with extra security you are using.
  • Always list the version of the IDE you are using and the board version if applicable.
  • How to insert an image into your post. ( Thanks Robin2 )
  • Add your sketch where applicable but please use CODE TAGS ( </> )
  • Add a SCHEMATIC were needed even if it is hand drawn
  • Add working links to any specific hardware as needed (NOT links to similar items)
  • Remember that the people trying to help cannot see your problem so give as much information as you can[/li

Bob.

There was a heatsink, I just removed it after the burning. I am 100% sure, wiring was correnct, since motor worked, then burning happened. But, I did not adjust current to be honest, although I don’t think it is about the current limiter since, as far as I know, current limiter is for the motor protection and not for to protect the driver. Currect me if I am wrong.

The current limiter is a very important part of the whole setup.
Without it you can suffer stalls from under current, or worse try to demand more current than the driver is really capable of.

You may get away with it for lighter load usage but it still not something that should be ignored.
Most of these drivers run warm or hot to start with.

In my case I have a small salvaged fan blowing across mine as I run them at 36 Volts and close to max Amps.
Not lost once since doing that but previously even with the correct settings I could occasionally lose one as my CNC does often run some deeper cuts which draws more current.

I would like to refer you back to the posting tips though as we have no idea how you use them and with what.

Bob.

EDIT...Some of the heatsinks supplied from China have a self stick pad that can become soft with excessive heat and the heatsink can move and with some of these driver boards can short out pins.
With mine I use a fine diamond finishing stone (3000) to smooth the heatsink and then use a small dab of super glue. This ensures a close contact to the chip and no movement of the heatsink.

ballscrewbob:
The current limiter is a very important part of the whole setup.
Without it you can suffer stalls from under current, or worse try to demand more current than the driver is really capable of.

You may get away with it for lighter load usage but it still not something that should be ignored.
Most of these drivers run warm or hot to start with.

In my case I have a small salvaged fan blowing across mine as I run them at 36 Volts and close to max Amps.
Not lost once since doing that but previously even with the correct settings I could occasionally lose one as my CNC does often run some deeper cuts which draws more current.

I would like to refer you back to the posting tips though as we have no idea how you use them and with what.

Bob.

EDIT...Some of the heatsinks supplied from China have a self stick pad that can become soft with excessive heat and the heatsink can move and with some of these driver boards can short out pins.
With mine I use a fine diamond finishing stone (3000) to smooth the heatsink and then use a small dab of super glue. This ensures a close contact to the chip and no movement of the heatsink.

I see, thanks for the tips and the answer. With the new driver, I did adjust the referance voltage just in case. If this one burns down again, I will be sure to include much more detail.

I learn a lot from my own mistakes and the mistakes of others LOL.
This forum has probably the best people who pass on thier own experiences and skills.

I am still a noob in so many respects.

Disconnecting the motor while the chip is powered will instantly destroy the chip. Make sure that the connections are cleanly soldered, and don't change wiring while powered up.

Also, breadboards should never be used for motor connections, as the high current will burn the tracks, leading to the same problem.

compnaion:
But before it happened, I connected and disconnected 24V input from the driver several time, while I was uploading code to the arduino and I have seen some little sparks on the pin while connecting it back. Can it be the cause the burning? If so, in what order I should connect and disconnect the driver while I am connecting arduino to pc and disconnecting it.

Do not do that while uploading code.
While up loading your I/O pins change state, this could have caused the controller H-Bridge to turn ALL MOSFETs fully ON and fault currents to flow through the control chip.

When you disconnect, disconnect the positive of the supply.
Use a switch, not two bits of wire twisted together.
DO NOT switch or modify your circuit while uploading.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom... :slight_smile:

ballscrewbob:
I learn a lot from my own mistakes and the mistakes of others LOL.
This forum has probably the best people who pass on thier own experiences and skills.

I am still a noob in so many respects.

Me too :smiley:

jremington:
Disconnecting the motor while the chip is powered will instantly destroy the chip. Make sure that the connections are cleanly soldered, and don't change wiring while powered up.

Also, breadboards should never be used for motor connections, as the high current will burn the tracks, leading to the same problem.

So, I should always disconnect the 5v chip connection first then, right?

TomGeorge:
Do not do that while uploading code.
While up loading your I/O pins change state, this could have caused the controller H-Bridge to turn ALL MOSFETs fully ON and fault currents to flow through the control chip.

When you disconnect, disconnect the positive of the supply.
Use a switch, not two bits of wire twisted together.
DO NOT switch or modify your circuit while uploading.

Can you please post a copy of your circuit, in CAD or a picture of a hand drawn circuit in jpg, png?

Thanks.. Tom... :slight_smile:

This is exacly how my connections are minus capacitor. I don't have a capacitor. But the 24v power supply is of high quality.