H-Bridge Secrets

This tiny corner of the world-wide-web is dedicated to H-Bridges. This project started with an H-Bridge I worked on a long time ago. Later it expended to the original ‘H-Bridge Secret’ articles, a 3-piece series detailing my experiences. Since then I’ve worked on other projects, thought a lot about the problems and learned a lot. That’s how this new series came to be. You’ll find much more details and explanation about the operation of the H-Bridge then in most on-line literature – at least the ones that I came across. It is a live list, where I’ll add new articles as they become available. So far you can find the following pieces:

  1. H-bridges – the Basics
  2. Sign-Magnitude Drive
  3. Lock Anti-Phase Drive
  4. Asynchronous Sign-magnitude Drive
  5. MOSFETs and Catch Diodes
  6. H-Bridge Drivers
  7. H-Bridge Control
  8. Safety Features
Print Friendly, PDF & Email

20 thoughts on “H-Bridge Secrets

  1. Pingback: High Performance Wine Storage System #4: The Main Board « Patrik's Projects

  2. Incredible source of quality information!
    Many thanks for your efforts and for demystifying the subject for a layman like me.

  3. Pingback: A basic question on Sine Wave Inverter

  4. Pingback: Derivation of formulas to estimate H bridge controller current (Vex, JAGUAR,Victor) « Vamfun's Blog

  5. Hello,

    Thank you for these articles. I’m referring to you on my blog. Your infos are quite unique on the web, very well explained, exhaustive, well researched, thanks!

    I’m building a prototype BLDC controller, I’ll follow your advice to drive my H bridge. This is an educational project, so it was important for me to understand mos driving with discrete components.

    Integrated black-box driver chips were not interesting for me at this stage.

    Thanks again!

      • Thanks for the PDFs. But in the section ‘Lock Anti-Phase Drive’, 2 pictures are missing. One should follow the words ‘the motor is 0:’ and the other follows ‘forward direction:’. Can you check this? Thanks

  6. Hello, I’m undergraduate in Inha Univ. in Korea.
    I’m learning about motor and I find modularcircuits.com.
    I can learn about H-bridge, a lot. Thank you for your documentary.
    But I have a question about PWM drive modes.

    There are Sign/Magnitude drive, Locked anti-phase drive, etc in your documentary.

    But I learned about Unipolar, Bipolar, Complementary and Independent PWM drive modes in here.

    What is different between your and my terms.

    I’m sorry because of my terrible English skill and Thank you for reading.

    • Park,

      Unipolar is another name for sign-magnitude while bipolar is for lock anti-phase drive.
      Complementary and independent – at least in the cases I’ve seen it used – refers to the generation of the PWM pulses on a (micro)controller. It’s not necessarily a given, but complementary mode is most useful to implement lock anti-phase or synchronous sign-magnitude drives, while independent mode could be useful for asynchronous sign-magnitude drive.

      I hope this helps,

  7. Hello Andras, I appricate your clear explanation of the H-bridge technology.
    Unfortunatly my inductive loaded H-bridge creation is suffering from distortion.
    And so far i cannot find a solution on the internet. I tried commercial H-bridges with similar effects.
    Sinds you know a lot about this field I would like to ask your help.
    Do you have time and relish to look into the matter?

    • I’m not sure I understand what yo mean by ‘distortion’ in an H-bridge. Are you talking about a class-D amplifier? Please elaborate.


Leave a Reply

Your email address will not be published. Required fields are marked *