Ok if anybody saw my previous post about my Dash-9 you will know that I have come to the realization that I need a larger power supply. Does anybody know a decent controller that has enough amp capacity, and is yet in-expensive, to complement the Crest 10 amp power supply? I wanted the Crest 10 amp controller but it is PWC, and I have read that PWC is not a good idea with sound systems, which all of my engines currently have, except the Dash-9. Any help would be greatly appreciated!
Matt
Uncle Joe, What does PWC stand for?
Matt,
It’s Pulse Width Control. Ok with that said I don’t understand it myself and now have asked about it myself somewhere else. I’ll keep you posted [:)]
Take care,
Jack
Thanks Jack. I don’t quite understand PWC either, all I read about it was that sound systems don’t seem to be that compatible with it, which would pose a problem for me.
Matt
PWC or Pulse Width Control (sometimes called PWM- Pulse Width Modulation) refers to the waveform of the power being applied to the track.
Imagine that you could flip a switch very, very quickly and that the switch was connected between the power supply (set at 20Volts) and the Track. If you toggled the switch such that it was closed exactly the same amount of time that it was open, you’d be applying power to the engine for only half of the time. That’s called a 50% duty cycle. In a given period of time the power is on half the time and off half the time, the average is 50% or 10 volts. In reality this switching is done electronically and occurs thousands of times a second. So if you varied the ratio of on time to off time you would vary the average power and thereby vary the speed of the motor.
PWC is used to improve the low speed torque of the motor. Again, the switching is done electronically of course and it is done at a very high frequency. This high frequency switching creates transients (electrical noise) that interfere with the sound system.
Walt
Thank you for that information Walt. That actually makes a lot of sense now. Now if only I can find a controller…
Matt
High frequency means that small inductors can easily filter the noise. Also, voltage regulators combined with a full wave rectifier and capacitors will reduce noise to levels less than a strong radio signal.
Of course this equipment needs to be engineered into the circuit.
Oh don’t even get me started on full wave rectifiers and capacitors. I started courses in Electrical Engineering and all I’m going to say is, I’m going to be a history major. [:)]
Matt
Matt,
Walt’s description is just about spot on for what I’ve been finding out. You could also goto the Aristo forum and look for the topic “What exactly is PWC ?” there is a link supplied in that one that gives a real good visual presentation of how PWC works. So to me it looks like you would only have the PWC if you used Aristo’s controller or the Trackside Train Engineer.
Take care,
Jack
Again, thank you Jack and thank you Walt for the information. If anybody could direct me toward an inexpensive controller that would be compatible with the Crest Ultima power supply it would be much appreciated.
Matt
PWM as we call it here in Australia is a great thing, I was in the UPS industry for nearly 20 years and that is what is behind a lot of UPS’S and there are some very technical and high class blokes in that industry and if they love it so do I.
For those who do not understand; this has nothing to do with PMS.
rgards ian
How about Aristo’s own 10 amp controller? A friend of mine’s very happy with his. It’s in the front of the catalogue
Ian,
Ah, but there you are indeed mistaken! When she has PMS, you get out your PWC and go hide in the back yard playing with your trains; thereby , using that old adage of “Out of sight, out of mind” to avoid being clobbered, mutilated, or even worse, being made to cook dinner. It is indeed a quite useful invention rather applicable to the welfare of mankind!
Hey there,
Currently I use Aristo’s small transformer for outdoors. My locos have Sierra sound. So far no problems! Hope you find what you need. Later eh…Brian.
Brian-
You don’t have any problems getting the voltage activated sounds to occur with your controllers? I heard those were the types of problems people were encountering. Also, does anybody have the MRC Power G transformer? I just discovered it searching the web and figured I’d check on here to see if anybody has it or would reccomend it.
Matt
I have a MRC Controle MAster 20 not shure if this is the same thing. als i know that my CM20 works very very well.
I went to there web site MRC’s www.modelrec.com
I think 229.99 is a bit to much for a power suply.
i have also used a transformer for low voltage lighting. i think you could hook it up to as the power suply. i think it has over 10 amps.
i think there prodagy DCC system looks good, i have been looking into it for some time now.
I saw the MSRP on MRC’s website as well so I decided to check some other prices…$139.99 at my “supplier” for the MRC Power G. I won’t post who it is here because I’m not getting paid for endorsements. But if anybody else has any comments on the Power G they would be much appreciated.
Matt
There is the Feb 2003(?) GR mag review which makes it a very promising replacement for my PHHobbies PS-10G which just today decided it would not work . . with snow coming tooo !
http://www.trains.com/Content/Dynamic/Articles/000/000/005/029agoqf.asp
Found it listed down in the u.s. online for $137usd ! Shucks if I can find it up here for that price or close, I’ll snap it up on Monday vs an emergency repair on the PS-10G.
Then get the PS-10G repaired whenever possible, for use indoors . . . .
nite,
Doug C