On Tue, 17 Jul 2001, Mike DeMetz wrote:

>  I probably have one for an old ACE servo. ACE provided complete
> schematics/theory of operation of all their radio equipment(since many were kits)
> and you could order every part/component.They used the Signetics NE544 as most
> all servos of the 70's-80's did. According to  https://www.fmadirect.com/home.htm
> all of todays servos use the same Mitsubishi chip but I don't know if it emulates the
> old Signetics chip.
>  I also have a book with circuits from 60's-70's
> >
> > Related to the other thread, about driving servos, does
> > anyone happen to have an actual schematic for the internal
> > electronics for a 3-pin, RC-model type servo?

Actually I have seen two different chip types in the last few months.
One (Airtronics) uses a single IC, the other (Futaba) uses a pair, one
servo logic/timing and one H-bridge driver.  I found schematics of the
2-chip version on a robotics page -- don't have it with me, but I think
it was the PARTS web site (Portland Area Robotics Society, I think), which
is a really cool place to visit.

Dale
--
A train stops at a train station.  A bus stops at a bus station.
On my desk I have a workstation...

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