L298N - Supply voltage problem

I am having some problems with L298N H Bridge driver ( Motor Driver 2A Dual L298 H-Bridge [L298N] - US $4.00 : HAOYU Electronics : Make Engineers Job Easier )
This is my configuration on driver:

  • no connection on pin input and output ( no motor connected )
  • no jumper on pin enable "EN1" ,"EN2"
  • jumper connected on pin 5V regulator "5V_EN"

Now connecting a 6v battery pack ( 4 battery x 1,5) on pin "12v" e "GND" looks like to go in short circuit
and l298n it remains off. The voltage on two pins connected is 0,5v, why?

Furthermore connecting the "5v" pin of my arduino board at pin "12v" of l298n (gnd linked togheter), arduino turns off and voltage two pin "12v" and "gnd" on l298n again go 0,5v.

Why this behaviour?

Haven't used this before, but its always good to review the schematic (its in the link you've provided) and the datasheet for the driver.

I took a quick look at the datasheet and a few things looked quite important:

  1. Vs (the supply voltage) needs to be (at minimum) VIH (5V) +2.5V = 7.5V.
    Can the battery supply this voltage or the expected load current or both?

  2. Look at the block diagram and you'll see why you can't leave the enable pins disconnected.

jumper connected on pin 5V regulator "5V_EN"

To where?

Furthermore connecting the "5v" pin of my arduino board at pin "12v" of l298n (gnd linked togheter), arduino turns off and voltage two pin "12v" and "gnd" on l298n again go 0,5v.

Not a good idea. The Arduino could never supply enough current (or voltage) to power up this driver board. Review the schematic and datasheet.

Why does the voltage go down to 0V?

In this configuration connecting a 9v battery on "12v" pin works correctly ( led turn on and voltage on pins is 9v).

davdilorenzo:
Why does the voltage go down to 0V?

What voltage? What pins?

davdilorenzo:
In this configuration connecting a 9v battery on "12v" pin works correctly ( led turn on and voltage on pins is 9v).

At least here you have sufficient voltage to make it work, but ... what configuration? As in your first post? Are the enable pins tied high or low or left floating (unconnected)?

Voltage between pin "12v" and "Gnd" with 4 battery x1.5v.

Yes , the configuration writte in the first post.

Enable pin are floating(unconnected)

Enable pin are floating(unconnected)

Check item#2 in reply#1.