12C509 to MOSFET H-Bridge ... how to avoid shorts?
Bob Blick email (remove spam text)
At 05:22 AM 10/3/98 +0000, you wrote:
>I wish to have bi-directional PWM control over a small toy 9V DC motor,
>from a PIC 12C509, so I guess I would set up a H-Bridge using four logic
>level MOSFETs, but I have a few newbie questions;
I've enjoyed the responses you've gotten so far. Why not use $$$ of parts
to control a $ motor? Because it's not sensible!
If you want a small H-bridge, get an H-bridge IC. DO NOT use an L293D(an
H-bridge that is popular on this and the Stamp list) if you are using
battery power - it will consume more quiescent current than your motor.
There are lots of available parts, I am most familiar with those made by
ROHM. The company I work for uses lots of BA6208 and I think they cost
about US$0.35 in 5000 quantity. Even if you buy them in onesies from
PartsExpress they will cost about US$1.35
The BA6208 will not self destruct from any logic combination. It draws no
quiescent current. I've found it to work up to 300mA pretty well. If you
need bigger devices, ROHM makes them.
If you really want to make an H-bridge yourself, take a look at:
or for a pc board layout:
for some ideas(it shows a 100 watt h-bridge, but the idea is the same), and
you can follow a link for a PWM generator in case you don't want to
generate PWM from your PIC.
See also: www.piclist.com/techref/io/motors.htm?key=h%2Dbridge
You must be a member of the
piclist mailing list
(not only a www.piclist.com member) to post to the