L298 voltage dop too big?

I have a 4 motors to control the movement of my buggy. I'm currently supplying it with 25.5V to make up for the potential drop (I'm aware l298's are quite ancient and have a 50% p.d drop), but surely 12.75v is enough? I'm not sure if I wired something wrong or if something else is the issue?

Hi, @missingnemo2004
Welcome to the forum.

Please read the post at the start of any forum , entitled "How to use this Forum".

This will help with advice on how to present your code and problems.

Please post your code and a schematic.
Please post links to motor specs and data.

12.75V? Between what points are you measuring the drop.
How hot does the 298 get?

Tom... :smiley: :+1: :coffee: :australia:

read this thread, may be a hint there...




Sorry but you must "elaborate".
Please answer questions and requests in post #2 .

You have the project infront of you, we don't.
You know how it is wired, we don't.
You know how you are powering the motor and arduino, we don't.
You know how you are outputting digital logic to the H-Bridge, we don't.

Tom.. :smiley: :+1: :coffee: :australia:

sorry :slight_smile:
thank you for trying to help out
Firstly my project is going to be an IR sensor line robot
I haven't incorporated them into the circuit yet because nothing else works atm.
As each of my motors require 5/6v to run, putting themm in series meant 24 volts is required at most, so i thought of putting it in parallel, so 12v at most is required. I've heard h-bridges in parallel isn't... ideal to say the least, so I'm wondering if should get a completely differnt component or whether what I have in mind will work.

My circuit:

Ik 9v isn't enough but i'm quite sure it would blow up in my face spectacularly.


I'm sorry but the resolution of that image is not good enough to read.
Also it looks like you have not included the L298 and ALL its pins and connections and power supply.

A 9V smoke detector will not have enough current?

Please a full diagram, and point out where you get the 12.5V drop.
A picture of your project will help a lot also.

Thanks.. Tom... :smiley: :+1: :coffee: :australia:

  1. Have you read the thread posted above?

  2. The drop is not that big. A motor powered by 12V will receive ~10-11V. I measured it with a multimeter a while back. Where did you read this? What kind of L298N are you using?

I read it as a part of another forum. People referred to the l298n as "ancient technology" and that they werent surprised by such a large drop in the voltage.

Yes, the chip is old, but the voltage drop shouldn't be that bad. Test with your own multimeter, I could be wrong, but I don't think I am.

EDIT - Also, please answer the other two questions so we can help you further. No information = no help.

I'm qutie sure this was the one i read earlier adn they were all talkin gabout hwo large the heat sink was and how innefficient it was. So I put them in parallel.

I don't know if there's an actual voltage drop of 50% - like i said i just read it somewhere. I'm only assuming because i think the rest of my wiring doesn't seem wrong...

Hi, @missingnemo2004

  1. Where in your picture is the controller.
  2. A smoke detector battery will not provide the current your FOUR motors need.
  3. Where is the 25V supply you were talking about.
  4. PLEASE.. PLEASE.. draw a proper circuit diagram, where is your controller, make the motor symboils smaller and the motor controller and where ever the Arduino controller is BIGGER and show component names and pin labels.
  5. You have been asked for a link/specs to the motor driver, WHERE ARE THEY????
  6. You have been asked for your code, WHERE IS IT??????

Big question;
I'm sorry but what is your native language?

Tom.... :smiley: :coffee: :coffee: :coffee: :coffee: :australia:

1 Like

Where did you read this crap?

My native language is malaylam.
Also I'm fully aware that this is an arduino forum which means i'm meant to be using arduino - but I'm not. I'm using raspberri pi. Their forums didn't respond back so I thought I'd try here.
Do I need a generator of sorts to provide the necessary current to power 4 motors?
I just had a load of batteries lined up in series to make 25 volts and I used it as part of the complete circuit in series once and the wheels still didn't turn so I bailed - definetly would have blown something up.
I will redraw the circuit diagram just when it's morning here

A link that has some info on the spec, i hope it's enough
the code

I would think that all of nine people here know Python. Ask Reddit.

EDIT - Maybe I'm just a bad maker for not knowing Python :slight_smile:

Nope, found no use for it.

Tom... :smiley: :+1: :coffee: :australia:
PS, I have a Pi4, still in its beginners box.

I broke two in 6th and 7th grade.

It was very expensive.

My 1GB model has held up being a RetroPie and an OctoPrint server. It's next task is to sit in a box until I can figure out what to do with it.

Python nand RPi are useful add ons !
Worth tinkering with