H_BRIDGE SN754410 problem

Projects General Guidance
1

Hello everyone,

I am working on a project that requires pushing of an actuator. I am using an Arduino UNO and a SN754410 H-bridge IC.

SN754410 datasheet: http://www.exploringarduino.com/wp-content/uploads/2013/06/SN754410-datasheet.pdf

To understand SN754410 I read chapter 4 of exploring Arduino, link: Chapter 4 | Exploring Arduino

I followed the tutorial and everything worked perfectly! Attached is my circuit for the H-Bridge.

Then, recently, I had to switch the circuitry to another breadboard and when I tried the circuit it no longer worked :confused:

I have tried to:

  • Chage chips
  • Change the breadbard
  • Changing the pins used from the Arduino

But none of these have worked.

I have measured every pin with a volt-meter and noticed that the pin 2A on the SN754410 does not go LOW (Pin connected to D5 of Arduino stays at 2.10V) when it is supposed to.

This behavior only happens when I have a power source, 12V, connected to Vcc2. If there is no source on Vcc2, the pin goes LOW and HIGH like it should.

I still don't understand what went wrong, it was working perfectly before!

I am looking for any help on what I could be doing wrong or what is wrong, I am happy to answer any questions to clarify anything!

Thank You!

Actuator Circuit.png
Actuator Circuit.png1132×669 7.84 KB

2

Basically breadboards are crap. You need to solder things up.

3

Grumpy_Mike:
Basically breadboards are crap. You need to solder things up.

Haha true!

I did forget to mention that I created a PCB for the H-Bridge and still had the same problem so I was hoping there was a problem on my circuitry or that someone else ran into the same problem

4

Be careful not to blow up the Arduino: if the voltage on the pin is this high, it means that a lot of current is flowing into D5.

Pieter