17 years ago
I've tried the Jaycar forum, but their moderator must be asleep as the post
hasn't appeared yet.
The setepper motor works fine from about 30 rpm up to about 300 rpm, after
which it just vibrates back and forth between steps very fast without
rotating at all!
Is this likely to be a bung IC (555 timer, or "GAL16V8D 15LP D246DD16") or a