Ok let me get this straight There are three types of magnetic uncouplers. Electormagnetic- Activated uncoupling with the push of a button Instant Uncoupler magnet- Uncouples upon cars passing over it. Delayed Uncoupler Magnet- uncouples after a coupler is "Spotted" over the magnet. Am I right? And by "Spotted' what are we talking in terms of time...1/2 second...or is it just slow uncoupling so a moving train would stay coupled. These stand alone magnets still work after ballasting over them right?