DarrellR posted:Nice design and very nice boards!
As you pointed out in your posts, the decoder's AUX outputs act as low-side switches, so sometimes you might want to use "low-side" high-power switching of a device, controlled by the decoder AUX output. This application sometimes arises when you have common-power supplying multiple devices, and the decoder’s AUX open/ground outputs control each device separately.
In this case, you might employ a pair of N-channel MOSFETs in a package such as ZXMN3G32DN8TA (similar to the DMP3085LSD-13 package in your post) in the following straightforward circuit.
Yep, agree an approach like that should (and obviously does) work also.
I'm always looking to minimize parts count, partly to keep things as small as possible, but also because I'm putting them together by hand, so every part means more assembly time! Hence, the approach described above.
Related question - I thought that ESU smoke unit was supposed to be basically a drop in hookup with the Loksound L in a normal installation. You are using the switching circuit here just to run it off the decoder tester, I guess?
