670: electromagnetic trip: power to an isolated
rail section goes through
a coil which pulls contact closed when a loco is receiving power in the
isolated zone. Contact opens when track power is cut off. Some 670's are
adjustable to a degree w an adjustment screw; some are not. Problems: 1.
Not all that sensitive and accurate, often slow acting. Performance
depends to some extent on amount of track power at any given time (i.e. how
fast train is running). 2. causes power drop since the coil uses some of
the track power. Locos will slow or stall in the isolated zone, especially
2 motor diesels. Generally not good for use in reverse loops where
polarity is reversed by a track switch. Good in an area where you may want
to stop a train, since contact will open then and not burn out an
Lockout eliminator: has nothing to do per se with
track trips. Used with
train stopping accessories, esp the 761 semaphore. An isolated zone is
created to stop a train; with the semaphore, in the base post rail.
Lockout eliminator allows a trickle of electricity into this zone so the
reverse unit does not cycle. Sam the Sem, talking station have them built
in. New locos from LTI and AM will often creep in such a situation because
they use much less power than classic Flyer.
Hope this helps.