Shop OBEX P1 Docs P2 Docs Learn Events
Nuts & Volts article - High Power H-Bridge — Parallax Forums

Nuts & Volts article - High Power H-Bridge

ArchiverArchiver Posts: 46,084
edited 2003-05-31 23:53 in General Discussion
Ever had one of those days?

I'm attempting to build the above circuit (Sept '99 I believe)

I've followed the parts list perfectly, built the circuit, double and
triple checked it. Nothing.

The stamp seems to be doing what it is supposed to, but the 4081 doesn't do
a thing. With a logic probe I can see the stamp trying to PWM the 4081,
but the output side of the 4081 never changes.

I'm not in any rush for a fix, this is just for fun anyway, but I am
quitting for now and going fishing (hear teeth grinding)

Any tips where I can begin to look for my error?

The code compiles (so to speak I guess) fine, the only change I made in the
code besides some debug statements to see where I am is the REVERSE lable
appears to choke pbasic. I don't know if its a reserved word now or what,
but I changed it to GOTHEOTHERWAY and it works fine.

Any suggestions would be appreciated.

Thanks,

-John

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-05-31 23:53
    --- In basicstamps@yahoogroups.com, John Walton <john@l...> wrote:
    > Ever had one of those days?
    >
    > I'm attempting to build the above circuit (Sept '99 I believe)
    >
    > I've followed the parts list perfectly, built the circuit, double
    and
    > triple checked it. Nothing.
    >
    > The stamp seems to be doing what it is supposed to, but the 4081
    doesn't do
    > a thing. With a logic probe I can see the stamp trying to PWM the
    4081,
    > but the output side of the 4081 never changes.
    >
    > I'm not in any rush for a fix, this is just for fun anyway, but I
    am
    > quitting for now and going fishing (hear teeth grinding)
    >
    > Any tips where I can begin to look for my error?
    >
    > The code compiles (so to speak I guess) fine, the only change I
    made in the
    > code besides some debug statements to see where I am is the REVERSE
    lable
    > appears to choke pbasic. I don't know if its a reserved word now
    or what,
    > but I changed it to GOTHEOTHERWAY and it works fine.
    >
    > Any suggestions would be appreciated.
    >
    > Thanks,
    >
    > -John


    keep your tip up and use live bait.

    first, make sure you are driving the transistors/darlingtons/mosfets
    with enough power.

    you should be able to verify the circuit without the stamp.

    then check stamp output volts/amps to verfy that it complies with the
    final device.

    then look at software. if you want to prove the software first,
    switch out the driver chips with LED's.

    Dave
Sign In or Register to comment.