I am not a fan of Sterns flipper system. A single coil winding that is "pulsed" when in hold mode creates a lot more issues than the pennies saved by doing it this way saves I believe.
But what would I know.......
Im not familiar with Stern flippers at all ( surprise surprise), but im assuming there is no "holding" winding on the coil and the pulse is switched quicker than the flipper can drop due to no current through the coil?... Prevents overheating of a single winding I guess but can see that its probably a fine line being trodden here and the coil would probably suffer from continued use.
