Noob in need of help powering 2 DC motors

Other Hardware Motors, Mechanics, Power and CNC
1

Hello everyone!

I am in need of help as I am only good with mechanics and coding but terrible at electronics.

I want to power 2 DC motors with the L293D motor shield (v1).

The motors are run at 13000 max RPM at 6V.

I currently power my Arduino separate from the shield and power the shield with a 6V battery pack. I've tried to hook-up just 1 motor and have failed to get it to run. It runs when i give it a little spin at the beginning of the program but otherwise it just makes a constant beep sound and doesn't move. I also noticed the ICs get pretty hot so that worries me since the motors dont even move.

The code is a basic FORWARD at 255 and i know it works because I've hooked it to smaller motors and they work as they should.

However, the motors i speak of also spin beautifully and easily when DIRECTLY hooked up a 3V battery pack. Why is that? Is the power from the 6V battery pack lost somewhere inside the L293D shield? Should i get a bigger battery pack?

Any help would be greatly appreciated! I can answer questions about my hardware if more information is needed.

2

Have you checked the specifications of the motors and the shield? With no details given my guess is that the motors need more current than the L293 can supply.

Steve

3

6V is way too low a supply voltage for a darlington motor driver like the L293 - a MOSFET driver would be
way way more efficient and not lose 2.5V or more.

Please post full details of the motors.

4

@slipstick

this is the motor i'm trying to power

i hope that isn't the case!

these are the L293D shield's specs:

Features:

  1. to 4 bidirectional DC motors and 4 PWM speed controllers (approximately 0.5% resolution)
  2. Up to 2 stepper motor forward and reverse control, single / double step control, staggered or micro-step and rotation angle control
  3. 4-way H-bridge: The L293D chip provides 0.6A (peak 1.2A) current per bridge with thermal shutdown protection, 4.5Vto36V
  4. The pull-down resistor ensures that the motor remains stopped at power-up
  5. Large terminal blocks make wiring easier (10-22AWG) and power
  6. With reset button
  7. 2 large terminal external power terminals, to ensure logic and motor drive power separation
  8. Download Easy to use software library for rapid project development
5

MarkT:
6V is way too low a supply voltage for a darlington motor driver like the L293 - a MOSFET driver would be
way way more efficient and not lose 2.5V or more.

Please post full details of the motors.

my motor's description from site: "This 3-6VDC motor operates optimally at 6VDC, draws 450mA no load, stalls at approx 2.4A and spins at about 13K rpm. Measures 2" long x 1-1/16" dia with a little 3/8" dia x 5/16" 12-tooth gear. Simple +/- leads are wired to a double jack that can easily be cut off or jumped. Leads are 14” long."

6

What I would use, the price is worth it.

7

The motor stall current is specified as 2.4amps. That means the driver has to deliver at least 2.4 amps before the motor even starts to turn (stalled conditions) Your driver output is stated as a peak of 1.2amps so effectively you are grossly overloading your driver under stalled conditions.

8

Agreed, the L293 is totally unsuitable for your motors.

This motor driver from Pololu will work well, and they offer excellent product support.

9

Thank you everyone!

I'm back up and running.
Appreciate the support.

10

roytronics:
I'm back up and running.

In the interests of helping the next person with a similar problem, it might be an idea for you to describe your solution.