Motor Driver Heat Sinks

None of your motor drivers come with heat sinks and you don’t sell them separately. You could sell a version with the sink installed for a few more bucks and you could sell the sinks separately. I am using your TB6612FNG dual motor driver and it didn’t work for me without adding a sink. Pretty frustrating until I realized what the problem was. Yes, you can buy a generic sink and cut it to fit but it is hard to cut them without bending the fins. I would have bought one with the sink installed for me as a no-brainier.

A TB6612FNG board with mounting holes would be cool.

You could also have an option to include appropriate isolation caps for your drivers. I had to figure that out the hard way too! XD

Having product option check-boxes is an easy way to add revenue! Want a sink with that? Check the box. Want the right caps? Check the box.


We do not do the kind of thing you are recommending because there generally isn’t a “the right” heat sink or capacitor. If you are frustrated with there not being any heat sink, think of how annoying it would be to get the unit with a heat sink and find out it is too small to cover your intended electrical use or too big mechanically for your intended application.

Separately, I am not a big fan on counting on heat sinks from the beginning. If you are doing something low-power like what the TB6612 is for, there’s probably a fairly small range of motors that the chip can handle well with a heat sink but badly without it, and it would be better to just use a higher-performance driver for more current. If your solution ends up getting a little too hot, it makes sense to add a heat sink, but you still have to get one that fits the parameters of your installation.

Is your mounting hole request because you would use it for the heat sink, or for something else?

It’s a similar case with the caps: there are some already on the board, which should cover most cases; beyond that, the appropriate capacitors depend on the rest of your system. What capacitors did you have to add, and why?

- Jan

I am using the HP 30:1 micro metal gear motors. They couldn’t even free-wheel without over heating the driver at 9V. I went to Radio Shack and got a heat sink: Catalog #: 276-1368 and the driver works perfectly fine now. No need to engineer the heat sink. I didn’t do any and it works fine. Just get a beefy one that has lots of surface area that will fit. Why? Because there is a HUGE difference between no heat sink and with a heat sink. If it almost works w/o it then it will definitely work with no problems with one. Non-moving air around the un-sinked chip actually insulates it very effectively.

The mounting holes would let you mount the board to your robot/project if you are not soldering it to another board.

Without caps the motors would “sing” loudly. I put .1uF on each motor and that didn’t do anything but it is what the documentation recommends. Then I added a 330uF to each at the driver and that silenced them. The pdf for the TB6612 says you should put similar sized caps on Vcc. I put the 330 on but not the .1uF because I need to buy more. Ran out putting them on each of my SharpIRs. The 330 on Vcc didn’t seem to do anything but I really should have scoped it before and after to see if the noise came down. I might do that when I rebuild the proto-board. This is just a working prototype for now.

Thanks for the response and your time!

Are you saying you have 330 uF on the motor driver outputs? That would definitely not be appropriate, and it could account for some of your motor driver overheating (it might also kill those caps soon). I think the only legit way to deal with the singing is to use a PWM frequency that’s past what you can hear (typically 20 kHz).

- Jan

I got the idea for the 330uF cap from the last diagram on this page:

Where they placed the 470uF cap. I didn’t add the choke or the choke’s 2 caps yet though because the noise went away already. If I add those would that solve the heat issue with the motor driver?

About PWM frequency. I have found some documentation to change the frequency on Arduino Uno but not on the Mega2560, which is what I am using. I will do some trial and error with the Uno docs see if I can get it to work with the Mega2560. If you are anyone else knows some good docs on changing the Mega2560 PWM freq please post it.


Yeah, that setup, especially with just the big capacitor, is not very good for controlling the motor with PWM. Is your capacitor getting very hot? (Be careful touching it.)

- Jan

I took the caps off and the heat went away. The noise didn’t come back either though O_o

After I put the caps on the motor pins I also put a cap on the Vcc pin of the motor controller. Maybe that took out the noise? I might take it off to see.

Anywho, heat problem gone, noise problem gone.

Thanks for your time!