where to place the Diode?

Hello community,

I was sent a wrong motor drive, instead of L239D shield, I got a L239 shield. This is for controlling a 12v DC motor which is powered by a battery.

Can anyone guide me on where to place the Diode now? I have a IN4007 diode. Also, do I need a resistor?

If you are using the H-bridge you need not one but four, no resistor needed. Like this:-
Diodes.png

Ummm..

So first, I connect the motor driver shield (a simple version, even so,not a H-bridge alone to be clear) to the breadboard, place a diode in between both 3 and 6 pins, and then connect it to the motor?

Also, I am using just one motor, so only one side is active; do I still need 4 diodes or 2 are enough?

For bidirectional control of one motor you need four diodes.

If it is not a H- bridge and so the motor only goes in one direction you need to connect the diode like one of the two diagrams on the right hand side. The top one for a current source drive and the bottom for a current sink.

aksbonsra:
Hello community,

I was sent a wrong motor drive, instead of L239D shield, I got a L239 shield. This is for controlling a 12v DC motor which is powered by a battery.

Can anyone guide me on where to place the Diode now? I have a IN4007 diode. Also, do I need a resistor?

If you got a SHIELD, chances are the diode are already there.

What is the manufacturer and part number of the shield?

have attached an image for your reference just in case.

Hi,
OPs picture…
e566ce4186909e7a60d9e9b215a29a59b6621de3.jpg

Tom… :slight_smile:

AAHh.. now i see the button for inserting the pic!! :frowning: (new here)

Thanks :slight_smile:

Chip says L293D in the picture...

Ya learn sumfin every day here.. lol :o

Hi,
The D denoted different current devices.
293desc.jpg
Tom… :slight_smile:

Hi, also;
293desc1.jpg
Tom… :slight_smile:

Really appreciate everyone’s feed back here; Thank you.

I am afraid I am more confused than ever; don’t have any background in electronics (textiles person here)

Does this mean I have the wrong driver? I have 4 12V dc motors running separately from 4 different arduinos (UNO R3 and Leonardo) and they get activated by individual PIR respectively. They rotate forward and backward. (I had wanted them to stop, but I learned that motor uses most power when still, leading to heating sooner, and this has to run for 12hrs).

the drivers i got are L293 and L293D; two of each. Can i use them? still unclear, do I need a diode?

sorry, I know I am asking basic questions, which you probably have answered, I didn’t get it.

but I learned that motor uses most power when still

Well unlearn that it is rubbish. It only applies to stepping motors.

What motors have you got?

I have 4 12V dc motors running separately from 4 different arduinos (UNO R3 and Leonardo) and they get activated by individual PIR respectively

Sounds on the surface a very silly thing to do. You can do this with one Arduino.

They rotate forward and backward.

To do this you need a full bridge. As there are only two full bridges on one L239D chip you need two of these chips for four motors.

I know I am asking basic questions,

No you are not asking your questions basic enough. It seems like you haven't got the slightest clue as to what you are doing. You should be asking how to wire up your L239D chip, not where to put a diode.

aksbonsra:
I learned that motor uses most power when still

Grumpy_Mike:
Well unlearn that it is rubbish. It only applies to stepping motors.

Or a stalled DC motor, which is probably what the OP read but thought that meant whenever it's not moving?

Grumpy_Mike:
Sounds on the surface a very silly thing to do. You can do this with one Arduino.

To do this you need a full bridge. As there are only two full bridges on one L239D chip you need two of these chips for four motors.
No you are not asking your questions basic enough. It seems like you haven't got the slightest clue as to what you are doing. You should be asking how to wire up your L239D chip, not where to put a diode.

They are placed far, and this is my first ever project, so of course, I am still learning.

Thank you for your advice, I have learned how to place a L293D chip, I was asking for the L239 chip (I am unclear about the whole diode thing, does is already have inside the H-brigde or is it supposed to be on the said board?), if its not there, then where does the diode go on the board?

I am still unsure of using one board for 2 motors as they are to placed in distance with nothing in between them and I don't want wire hanging in between in air in the setup, that kills the aesthetics.

manor_royal:
Or a stalled DC motor, which is probably what the OP read but thought that meant whenever it's not moving?

YES!

Original plan was
PIR sensor senses motion and activates motor

Motor rotates forward for 3 seconds.
Pauses for 2 seconds.
Motor rotates reverse for 3 seconds.

Now changed plan

PIR senses motion and activates motor
Motor rotates forward for 3 seconds
Motor rotates reverse for 3 seconds

This will be in a loop for about 12 hours

I am unclear about the whole diode thing, does is already have inside the H-brigde

No.

or is it supposed to be on the said board

It could be, but the photograph you posted showed none.

Motor rotates forward for 3 seconds
Motor rotates reverse for 3 seconds

So you need two L239 or L239D chips.
The difference between the two chips are described in the chip’s data sheet, it says:-

The L293 is designed to provide bidirectional drive currents of up to 1 A at voltages from 4.5 V to 36 V.

The L293D is designed to provide bidirectional drive currents of up to 600-mA at voltages from 4.5 V to 36 V.

The diodes should be connected as in the left hand circuit given in reply #1 - REPLY#1 and you say you are not ignoring us!

The right hand side should be wired up just like the left hand side, so that is only two motors per chip.

dear grumpy,

No, I am not ignoring anyone, you are taking the time and effort to help me. I was saying I didn’t understand that. :frowning: