A DC motor controller with control LEDs


Boris Landoni writes about a new open source project a DC motor controller with control LEDs:

It can be controlled through logic levels to set the speed and the direction of the rotation of CC brushed motors and stepper motors; outputs have LEDs indicating the rotation direction.

The circuit board we are presenting this time is based on the dual-bridge driver L298N, in a traditionally mounted version in a Multiwatt container with 15 staggered pins; it has two terminal blocks for attaching to DC motors or the coils of a bipolar stepper motor and a terminal block for powering logics and motors. Each of the two output channels of the circuit can provide a maximum current of 2 A, which is enough to drive two 2 A direct current motors or a bipolar stepper motor absorbing 2 A per phase.

More info at Open-electronics.org.

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  1. Guys, for the next spin I would recommend strongly series resistors on inputs.

    A few Kohms gives a large protection against ESD and EOS events coming in on the driving wires for not much money. Overvoltages on the inputs as well as static discharges.

    If you use a SMT multipack resistor soldering is easy too, as you are already doing SMT.

    I am thinking pins

    6, 11, 5, 7, 10 and 12 (ENA, ENB, IN1, IN2, IN3, IN4).

    If you really want to go the distance drive the H-bridge through a socketed 74 series DIP buffer IC and again add series resistances on the buffer IC inputs. That way if you get a EOS it kills the throwaway 74 series, not the H-Bridge.

    Best, and good work,


  2. Really? They are digital inputs driven by an MCU. The MCU GPIO probably has diode clamps and ESD protection.
    Have you experienced such failures? Please give a pertinent example where the ESD and EOS comes into play.
    If you are thinking load dumps, then the MCU etc needs to be protected too.
    Look at the L298 data sheet, the input currents don’t look like CMOS to me. You mean bipolar TTL will get zapped too?

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