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Topic: Controlling DC Motor with L293 (Read 835 times) previous topic - next topic

tlestak

Hello,
     I am attempting to control a 24VDC, 1A motor using an Arduino Uno and L293 H Bridge.  I have been struggling with this as the motor has 3 ports to use, which I want all to be connected at once.  To spin ClockWise it needs +24 on 1 and -24 on 2.  To spin CounterClockWise, it needs -24 on 1 and +24 on 3.  The issue I have is with having Port 1 being connected to + and - at the same time, as this just grounds the circuit.  I am looking to remedy this issue with the L293 H Bridge and was wondering if the below set up and code will work or fry my components/ board (which I have already done once).  Thank you!

slipstick

Please provide a link to a datasheet/specification of that motor. I have a feeling you may be misinterpreting something in there.

And a hand drawn circuit diagram might be more useful than that strange Fritzy thing.

Steve

tlestak

@slipstick

Here is a link for the DC wiring diagram:
     https://assuredautomation.com/literature/IM/AA_R_Manual.pdf

I have attached a hand drawn circuit diagram.

TomGeorge

#3
Aug 24, 2019, 05:06 pm Last Edit: Aug 24, 2019, 05:13 pm by TomGeorge
Hi,
You are trying to control a valve actuator.

Quote
To spin ClockWise it needs +24 on 1 and -24 on 2.  To spin CounterClockWise, it needs -24 on 1 and +24 on 3.
The link you provided, the DC motor version has no pin 2 connection.
Although your schematic shows the correct pins.


The switches are on cams located inside the actuator housing.
Have you applied 24V directy to the terminals to prove that it does work CW and CCW?

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

TomGeorge

#4
Aug 24, 2019, 05:14 pm Last Edit: Aug 24, 2019, 05:16 pm by TomGeorge
Hi,
OPs Circuit;

The L293 is only rated at 1A, I would be using something a bit heavier in current capacity.
Tom.. :)
Everything runs on smoke, let the smoke out, it stops running....

tlestak

Apologies... In my original post I meant pins 1,3,4.  And yes I have been able to rotate the motor CW and CCW with the pins and by applying voltage directly across the motor.  However, I would like to use the pin wiring in my design to make use of the switches so I do not over rotate the valve.  I have yet to test out the L293 yet, but the motor only pulls 1A so I was thinking it should be okay.

MarkT

Some of these 24V valve motors stall at _1.9A_, not 1A, so you might need to parallel both channels of the L293D

By the way please give full details of the hardware, i.e. the precise model number, so we don't have to guess if
its the R-150, R-300, R-600.   Links to datasheet are good too.  https://assuredautomation.com/literature/R_actuators_datasheet.pdf
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

tlestak

@MarkT

The model number is R600B and the schematic can be found in my second post.

MarkT

As the datasheet shows the 600 model 24Vdc requires 1.9A, not 1.0A.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

tlestak

@MarkT

I believe the L293NE should be able to handle this as the output and peak output are 1A and 2A respectively.

http://www.ti.com/lit/ds/symlink/l293.pdf

jremington

#10
Aug 27, 2019, 11:32 pm Last Edit: Aug 27, 2019, 11:33 pm by jremington
Quote
I believe the L293NE should be able to handle this
Lots of people have similar beliefs initially, and end up buying a modern, much more efficient and capable motor driver, like one of these.

Unlike most other suppliers, Pololu engineers do not inflate the device ratings, and actively support their products.

tlestak

@jremington it seems as if you both are correct.  I set up my circuit as I have described above and am getting correct outputs with nothing hooked up.  However, as soon as I hook up the motor, I will only get an output of about .5V, no matter the input voltage.  I assume this is due to limits of the L293?

jremington

#12
Aug 28, 2019, 12:26 am Last Edit: Aug 28, 2019, 12:35 am by jremington
I don't understand your post. Where are you making this measurement?

Are you sure you have the L293 and not the L293D? If the L293, then external inductive kick diodes are required. As they are not shown in the posted diagram, you may have destroyed the chip.



Another reason to switch to a modern motor driver.

TomGeorge

Hi,
What code are you using to control your motor?
Can you post it please?

Thanks.. Tom.. :)
Everything runs on smoke, let the smoke out, it stops running....

tlestak

@jremington I was taking these measurements across the outputs of the L293NE where the leads to the motor would be connected (i.e. 1+ 3-).  When I take these measurements without the motor, I am getting the correct output.  However, when I attach the leads to the motor, the voltage drops due to the current draw being too high (I believe).  And I am sure that I have the L293NE.  I had not seen any documentation regarding diodes to I will look into that...

@TomGeorge the code I am using is in my original post.  It is named Motor_Driver_Test.ino

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