In the beginning I would just like to mention I don't have too much experience with electronics and English isn't my native language.

I would like to use a BTS7960 module with Arduino data sheet. Driving a 18v motor from cordless Dewalt Dcd785 drill and the only power supply witch is accessible for me is 24v 20A like this Is BTS7960 got a step down module or 24v will burn the motor?

Thanks in advance


1 Answer 1


That BTS7960 module is not a step down converter, however you can use it to run that 18 V motor at less than 24 V.

The BTS7960 needs a PWM signal (which you can generate with the Arduino), if that signal has a DutyCycle of less than 18V/24V = 75% then the motor should not notice the difference compared to feeding it 18 V DC.

If you go above 75% then in essence you're feeding it more than 18 V and that could damage the motor if sustained for too long.

Note that the currents which are going to flow between the supply, BTS7960 module and motor are significant. I mean, you MUST use thick cables which can handle that current and do not drop too much voltage. See the table on this page to see what AWG you need. If possible or when in doubt, use cable with more/thicker copper. Also make the cables short. It is better to have a long mains wire (to the supply) instead of long 24V cables.

  • \$\begingroup\$ Much appreciated Bimpelrekkie that clears everything. \$\endgroup\$ Oct 24, 2017 at 12:31
  • \$\begingroup\$ So in my understanding when writing a code for Arduino I cannot exceed motor speed over 191 units on 255 scale. Yes the cables are 2.9mm core solid copper should be able handle over 30A 100mm from power supply to bts7960 and 150mm to motor. Thanks for a quick answer. \$\endgroup\$ Oct 24, 2017 at 12:40
  • \$\begingroup\$ Yes, 191/255 = 75% should be safe indeed. Distances look OK to me as well. Good luck with your project! \$\endgroup\$ Oct 24, 2017 at 12:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.