Current limit in L298N H-Bridge

Projects General Guidance
1

Dear all,

I need to control a Peltier and a fan using an Arduino Uno and a power source (I am using 12 V, 20 A output from a computer power source). To control the fan and the Peltier, I am using a 2-channel L298N H-bridge, but I think there current that the Peltier and fan are receiving is much less than their need. I connected the Peltier, for example, directly to the power source, and its efficiency is much higher. Do you think that L298N is not a good board for my purpose? Do you have any suggestions?

Thank you

2

What amperage are we talking about.

Always show us a good schematic of your proposed circuit.
Show us a good image of your ‘actual’ wiring.
Give links to components.

Do you need to reverse current flow in the Peltier element ?

3

The links for the Peltier and H-Bridge are below:

The amp should be around 5A for the Peltier. Sorry that I have not provided the sketch. I have to draw it in fritzing and upload it here.

Yes, I need it. Because at one time, I may need to change the hot and cold sides. That is why I decided to use the H-Bridge.

4

What are the amps delivered by the L298 found to be?

5

The L298N is 2 amps :woozy_face:

6

Do you have any replacements in mind for the H-bridge?

7

LarryD said that it is just 2 A.

8

This is the data sheet, I suggest you look at the maximum ratings. Note the absolute maximum current is 2.0 Amps and if you are using a module the chip itself should have a good heat sink and cooling before even getting close to 2.0 Amps. That is per channel. Forget a 5.0 amp load.

Ron

9

Thanks Ron. So what do you use in my situation? Do you have any suggestion?

10
11

I think exactly what LarryD thinks. That is how I would go for the higher current needs. :slight_smile:
Ron

12

I assume you don't need to reverse the fan and you don't need to reverse cooling/heating of the Peltier. In which case you should not use a H-bridge at all.

A single logic level mosfet is all you need.
Use the first diagram from this page.
Leo..

13

Thank you all. But do you think this does the job?

14

No. It is not an H-bridge.

15

Does OP need a H-bridge ?
I guess not.

Yes, the modules are just a double-dose logic-level mosfet switch with the supporting parts.
A kickback diode is still required across the load when driving inductive loads,
but that's not needed for peltier elements.

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Leo..

16

Yes, according to post #3.

17

Ahh, sorry, missed that.

An MC33886 two H-bridge breakout board (ebay) could be an option.
(L298 on mosfet steroids).
Leo..

18

Thanks. I bought this one and will give it a try as soon as I receive it.