Crest Engineer vs Revolution slow speed

[astarr78]

I am runnung a 2 rail O scale RR with DC, drawing usually elss than 1 amp but as much as 2.5.  I am using a Crest Engineer on the PWM setting and love the low speed start up, effect it has on full brightness lights and smoke generation.  But I would like the locos to start moving at a crawl, even slower than the crest engineer.  Is there any reason to think that the revolution 57000 would achieve that?  I would be using the receiver as a stationary trackside device with the out put leads going to the track rather than the receiver mounted in a loco mounted.    

Thanks for listening

[two tone]

Hi   Post this in the general discutions  a member called Kevin Strong will see it and be able to help.

[piercedan]

The crest 27mhz and 75 mhz have programmable acceleration and deacceleration modes a-e.

A is fastest and e is slowest.  Have you tried this yet?  Are you talking these units or the newer revolution?

[astarr78]

I am using the older model engineer system at present.  I am familiar with the rate of acceleration by using a-e but I am referring to the lowest speed at which a loco will start moving.  I have a couple throttles that produce a strong "pulse power" that causes the loco to move less than one turn of the wheel per minute but they are not PWM type like Crest Engineer, so the "wave" is different and does not make the smoke and ligths and other features  work as well at low speeds. 

[kstrong]

I really don't have an answer. I want to say the new Revolution has a different PWM frequency than the older Train Engineers, but I can't find a single reference indicating what those frequencies might be, and why one might be advantageous over the other. I do know one danger of PWM frequencies is that if they're in the audible range, you can hear the motor humming as it gets power, especially at low speeds. I've not heard this on the Revolution, though I can't say I've specifically listened for it on railroads that use the older generation TE either.

Having said that, if you're comparing the slow-speed operation of the Revolution to a DCC-based system that uses BEMF or similar feedback to control the motors at slow speeds, the Revolution is not that sophisticated. I find the slow speed operation certainly adequate--I can move slowly through a yard for switching maneuvers--but I generally can't get the loco to crawl at a tie-per-minute pace. Quite frankly, though, I've operated on a number of railroads that do prototype operations, and no one's running their locos that slow. Even the prototype doesn't do that. It's a cool "show-off" feature, but from a practical standpoint, most operators simply want smooth starts and stops. Provided the motor and drive on the locomotive is smooth and free from binding, the Revolution is certainly up to that task.

Wish I had a better answer, but my experience with the older TE stuff is pretty much limited to public displays where I'm running club equipment. There, I'm not doing a lot of switching. I push the "go faster" button, Thomas starts moving, and kids smile. If Thomas stops, the kids get restless.

Later,

K