... sure which day yet. Your experience with Tortoise switch gear is the same as mine and sounds like it's common problem judging by the comments over the weekend on this thread. When you refer to solenoids for the other two examples, Merge and Peco, you then finish with a reference to servos? Were one of the boards controlling servos and the other solenoids, or have I just misread....not unknown To complete your education on frog juicers, well actuall not a frog juicer, but an Autofrog( same idea but 2787_101847_530000000.jpg uses a relay rather than solid state to change the polarity. The first picture shows the Autofrog first wiring up with a Wago plug stuck to the top as they don't come with proper terminals, just three solder pads, hence the need for something to make them unpluggable! The next shows one installed on the layout. Not a neat job but I've got it colour coded and I think with the records I've now got I should be able to understand it in a few years time when all this is but a distant ...