External diodes required on H Bridge motor driver?

[Mike Franklin]

Hello,

I have to drive 8 or so 12 v motors from a processor
and I'm at present thinking of using SN754410 as a dual
H bridge for each pair of motors. I expect < 1 A max but
haven't tested stall or anything realistic like that...
The actual application is automating audio equip controls
like vol.. The motors drive dual pots and one pot element
is used to determine position. I was driven to this
RubeGoldburgatron by my inability to locate any dual motor
pots in the desired resistance range, viz 1 Meg.

Questions:

- Do I have to put external diodes on the drive lines
for a 12 v brush motor? The app note circuit on the data
sheet shows 8 diodes for a stepper control. Internal driver
however looks like a Darlington pair w/ a diode snubber (I
think) so I'm hoping that will be enough.

- Is there a more integrated/better bridge chip that
I should consider? This one is ok, w/ two lines per
motor for the obvious control.


- Does anyone know of a source of 1 M dual motor drive
pots so I don't have to hack all this stuff w/ belts
on the non motorized pots I have now?

Thanks for any insight/suggestion you can offer..

mf