SJC posted:GGG posted:JohnGaltLine posted:GGG posted:MTH has always used relays to switch polarity and FET to control motor current, but continue to speculate. It is fun to do analysis without facts
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Probably why I've asked twice now in just this thread for information on the output stage of the MTH boards. Perhaps since you have so much experience with these boards you could (third time) post a photo or two of one of them. Perhaps share the knowledge and we won't have to speculate.
JGL
JGL, No time to post picture, but YOU could search the forum or internet and find them yourself. There out there.
Stan my term not MTHs. I did talk to Service about this post and it is a hardware issue that could be resolved via a revision to the board. Not planned at this point. The 3V used a diode to dissipate the energy of the motor when power cut off and hence the coast. The PS-3 design is different and unfortunately the motor gets shunted to dissipate the energy and that causes the abrupt stop of the motor. Does look like a diode is in there too.
MTH is aware but not going to redesign the board at this point. G
G...
Interesting post and info you have. The PS3 design is different than PS2 and as a result, this problem (no coasting) exists. There must have been a very recent change as my 2013 PS3 steamer DOES coast in conventional and has no issues. Same goes for diesels and twin motored steam. Perhaps it is just an issue with recent single motored locos.
Thanks for the info, I guess all I can do is hope there is a change, at some time.
What is the model steam that coast? Same for diesel? I would find it interesting you have a diesel that coast since those boards are the same. In steam there is the FET verses relay boiler board. It may be possible that a FET board coast but a relay board doesn't. (Relay steam is identical to Diesel as far as Motor control).
I just tested a PS-32 board I was loading a sound file into with DCS. This is identical to a PS-3 diesel board. I turned off power while the motor was spinning on my test set at 25 smph. It stopped almost immediately. G
