TL494 audio simple way

Discussion in 'General Electronics Chat' started by Motanache, May 16, 2017.

  1. Motanache

    Thread Starter Member

    Mar 2, 2015
    199
    18
    http://geekcircuits.com/2010/07/class-d-amp-using-tl494-dc-to-dc-converter-chip-2/
    TL494 Audio amplifier

    I made this scheme and worked very well:
    [​IMG]

    I do not have the MOS driver IC from the following schema:
    [​IMG]

    I do not have the IR2010 or any closer.
    What to use?
    I can use transistors MOSFET (N-MOS, IRF840) or bipolar.

    Create the driver from discrete components?
    Or try transformer for Gate drive?
    Anyway, I need dead time what is done by group D6 / R6 and D7/R7, D4/R3, D5/R4.
    For D6 and D7 I have neither the equivalent.
    I have 1n4007 but it's not a fast diode.

    How to do ? B-E diode of a transistor is good instead of fast diode?
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,966
    927
    A TL494 is a switchmode psu chipset not an Audio amplifier!
     
  3. bertus

    Administrator

    Apr 5, 2008
    16,437
    2,701
    Hello,

    @Dodgydave , They are using the TL494 as a class D modulator.
    @Motanache , You can not ommit the IR 2010, as it provides a boost converter to drive the upper mosfet.

    Bertus
     
  4. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,297
    2,228
    Are you sure about that? I was under the idea the TL494 incorporated drivers internally to drive the mosfets directly?
     
  5. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,599
    2,534
    You can use the 1N4007 in place of the 914 diodes. If you have another small 12 volt power supply and some small transistors you could build your own driver.
     
  6. Motanache

    Thread Starter Member

    Mar 2, 2015
    199
    18
    No, it has those two transistors as in the figure, which can be configured in any way.
     
  7. Motanache

    Thread Starter Member

    Mar 2, 2015
    199
    18
  8. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,966
    927
    1N914, 1N4148, are both the same high speed switching diodes,
     
  9. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,599
    2,534
  10. Motanache

    Thread Starter Member

    Mar 2, 2015
    199
    18
    I started by building the voltage source.
    Also with TL494 because I really like this IC:
    [​IMG]
    The problem is that I thought wrong.
    I thought he had reverse polarity protection:):):)
    I built it, it works well ,but if you change the polarity of the input voltage it's something similar to the circuithort-circuited.
    It is normal for the IRFZ44 to have antiparallel diode.

    Do you know any cheaper solution than to use yet another power MOSFET for inverse polarity protection?
     
  11. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,599
    2,534
    VD1 should blow the fuse with reverse polarity.
    You could put that diode in series with the 12 volts depending on the current you need.
    I think all the FETs have the diode.
     
  12. Motanache

    Thread Starter Member

    Mar 2, 2015
    199
    18
    It would be good to burn the fuse.
    But I'm afraid that first the power transistors(IRFZ44) are burn and then the fuse.
     
  13. ronv

    AAC Fanatic!

    Nov 12, 2008
    3,599
    2,534
    Don't worry, be happy. :)
    The body diode has a high current rating and a higher voltage drop than your reverse protection diode.
     
Loading...