Samuels Smith’s “Imperial” Stout you say?
I’ll have a look at the supermarkets and see if anyone carries the brew.
Thanks Benedict Fred, a connoisseur of fine bheer.
Dennis-
I am on MLS often, but just to look.
Someone has a problem I ca help with, I e-mail them, as I get tired of all the “experts” chiming in, and accusations flying.
See the one on the Bachmann Forum?
I answered the guy the most obvious, but someone chimed in and said to get a second opinion at the LHS.
I wonder how long my response to THAT will stay up?
TOC
What is the LHS? Lumbar Health Society?
Lousy Health System?
Local Hobby Shop.
Curmudgeon said:
Lousy Health System?Local Hobby Shop.
Of course. The source of all wisdom.
To all:
Hopefully this is helpful to those offering data as to any hazards from using these two Aristo (Crest) power supply components with USA, LGB, Bachmann, and other non-Aristo locos.
Since I started this thread, I’ll give more data per the Crest (Aristo) “Switching DC” power supply
[13 amps at 22.0 volts DC] I am using – along with the Crest model CRE 55401, rated to 10 amps, controller:
Crest "Switching DC Power Supply states in their literature:
“Highly filtered, no AC leakage”
“No AC Pulse power that can overheat fine motors”
“No noise interference with other electronics”
“Self-regulatilng output”
“Ultra clean signal”
Crest DC Train Controller (yellow box) #CRE 55401 states on the box:
“Consistent voltage pulse width speed cotnrol”
“Automatic electronic momentum circuit for smooth operation.”
“Automatic electronic circuit protection.”
The Elite is a switching power supply, but it has an output just like a battery. No pulses, no ripple like the Ultima.
The pulses come from the speed controllers and the trackside 27mhz unit has a PWC/Linear switch that a lot of us place in linear mode to please/appease the mfg gods that require linear power.
(Interesting to note that LGB has MTS which is a pulsing power as is DCC but these are waveforms on top of the DC level, not switching from 0 to max volts).
DCC is basically square wave AC, not DC, with basically a modulated frequency. The modulation in frequency is the data. Scroll down this page to see a DCC waveform http://www.wig-wag-trains.com/AHD/AHD_RRampMeter�_Product-Page.htm
Regards, Greg
Greg Elmassian said:
DCC is basically square wave AC, not DC, with basically a modulated frequency. The modulation in frequency is the data. Scroll down this page to see a DCC waveform http://www.wig-wag-trains.com/AHD/AHD_RRampMeter%99_Product-Page.htmRegards, Greg
Are you sure about that? I know in DCC that waveform (the one on the site your link goes to) works (which is what that site’s mostly about.) I was always under the impression, though, that PWC was exactly half of that waveform … everything ABOVE the zero line for one direction, and everything BELOW the line for the other … with the modulation being a controlled interval of “on time” for the half wave. That was also how their “linear” output worked; they put a capacitance circuit in the PWC line that “held onto” the on time for long enough that to the equipment it looked like linear DC… if you did this with a waveform that was as equally above the line as below, you’d have relative zero, and wouldn’t go anyplace… 0 -1 +1 =0.
Along those lines, with a DC motor, if you fed it the waveform in that picture, wouldn’t you have just as much backward direction power as you would forward, causing a buzzing sound, but not much motion? Since a PWC power supply is designed to run decoderless locomotives (i.e. motors more or less directly connected to the track) there’s nothing aboard to sort out the available power for a particular direction and speed like there is when you have a decoder on board to do it for you.
I admit that I could be completely out to lunch here … so if I’ve always misunderstood how this works, don’t shoot!
Matthew (OV)
Matthew.
I think you are right.
My only real experience with DCC has been with an early Digitrax Challenger system.
Personally I wouldn’t use it because of the noise.
As I understand it, DCC is actually a Bi Polar form of DC.
DC motors are controlled on the DCC waveform by stretching the zeros either way. If the frequency is low enough you can hear the motor buzzing either side of neutral with the buzz fading as the speed increases.
Most motors with iron cores can absorb the generated heat but “so called” coreless instrument motors cannot.
Experiments followed by production of dc servo systems where we deliberately introduced a 26 vac “dither” voltage on 28v dc motors to overcome stiction did not actually cause much of a problem ,the motor got warm but the reactance of the coils is greater than the dc resistance , so the wattage effect is lower . A similar stunt is pulled on dc operated hydraulic Moog valves , an ac signal , again , straight off the a/c 26 v supply , is applied making the valve "buzz " about its mean selected position and thus move with very little effort when called upon . The spool gets warm , but not excessively so . I am not sure why a coreless motor should suffer any differently,ours certainly didn’t , I am not suggesting it doesn’t , and would not chance it , but perhaps some enlightened chappie could expound ?
Mike M
TonyWalsham said:
Matthew. I think you are right. My only real experience with DCC has been with an early Digitrax Challenger system. Personally I wouldn’t use it because of the noise. As I understand it, DCC is actually a Bi Polar form of DC. DC motors are controlled on the DCC waveform by stretching the zeros either way. If the frequency is low enough you can hear the motor buzzing either side of neutral with the buzz fading as the speed increases. Most motors with iron cores can absorb the generated heat but “so called” coreless instrument motors cannot.
G’day Tony, Yes, that’s how it works. Chapter 3 in “Digital Command Control - the comprehensive guide to DCC” (ISBN 91 85496 49 9)explains the bi-polar signal and stretched Zero bit quite nicely. It will take a few more years of DCC before everyone gets the bi-polar DC concept. 
BTW what gets to the motors is PWM, the frequency depends on the make of the decoder. The dear old LGB-MTS 55020 decoders work(ed) at 80Hz and have/had such a nice hum at low speeds. Modern decoders (i.e ZIMO) have selectable frequencies as high as 40kHz. The new LGB-MTS3 decoder (55027) has a top rate of 16kHz and the lowest rate is 60Hz. Probably for those fans who are waxing nostalgic and really like that retro feel.
:lol: PS Running an analogue engine with stretched Zero-Bit on a DCC system will also generate plenty of heat. And apart from that it really degrades the performance of the DCC system, most noticeably so on the lower end systems which have slow characteristics to start with.
Hans-Joerg Mueller said:
G'day Tony,Yes, that’s how it works.
Chapter 3 in “Digital Command Control - the comprehensive guide to DCC” (ISBN 91 85496 49 9)explains the bi-polar signal and stretched Zero bit quite nicely.
It will take a few more years of DCC before everyone gets the bi-polar DC concept.
We now have medicines that will effectively treat Bi-Polar Disorder. Make sure that you see your doc. Oh… wait… Wrong forum. Sorry.
madwolf
Please.
Please, for those who actually have experience with the Crest (Aristo) “Switching Power Supply” using the 10amp pulse-width controllers (or maybe the power supply is the “pulse-width”), what is or are not the negative concerns?
Granted, the discussion did leave the initial question.
I’d appreciate knowing if I have, in simple wording, SCREWED UP and will end up cooking my LGB, USA, Bachman loco, and Hartland street car.
Several posts above, I listed the specifications that Aristo-Craft prints as to the qualities in both the power supply and controllers.
Thank you for any specific data.
Wendell
Wendell ,
many apologies , you are quite right , a lot of replies to your query (including mine ) are designed to show how clever the author is .
I apologise , having no experience whatsoever of your supply , I can only advise—when in doubt , keep out .
Mike M
PSEDIT Whoops , forgot the ;<)
Mike-
Many thanks for your thoughtful response.
You are likely are speaking for so many of us as we contribute to postings and so easily find we are bridging to related (or unrelated) topics.
Meanwhile, back to the topic: Considering Aristo’s claims on the packaging, I have a call into Aristo to hear what their staff states as to any “damage” concerns. My thought is if there is no concern, fine, I will reasonably ask that Aristo’s warranty support those printed assurances.
Who knows, rumors in this hobby are legion. Consider the phantom-yet-to-be-shipped locomotives consitently advertised in Garden Railways that are still yet to be produced.
Anyway…
Wendell
Wendell Hanks said:
Who knows, rumors in this hobby are legion. Consider the phantom-yet-to-be-shipped locomotives consitently advertised in Garden Railways that are still yet to be produced.Anyway…
Wendell
Wendell,
As someone stated Switching Power Supplies provide very clean DC - clean enough to be used in computer applications!
For what it’s worth have a look at this page which gives you the low-down on the old Ultimate PS http://www.girr.org/girr/tips/tips4/art-5460_tips.html and then check out this which is about the newer Switching PS http://www.girr.org/girr/tips/tips8/cre-55465_tips.html
Many of the “it will fry things” comments relate to the older Ultimate. So far I have only read one comment regarding the SPS which related to an unclamped voltage. And if I remember correctly, the possibility was hotly disputed by Aristo.
I have used different SPS for model railway applications for many years (no, I don’t have an Aristo unit!) and have never had even the smallest, slightest problem.
BTW George Schreyer also has write-ups on the Aristo controllers etc. etc.
http://www.girr.org/girr/tips/tips.html
PS There are some LS manufacturers who would have you believe that their equipment will only work properly when used with their own controls and power supplies. Of course I have yet to find any electrons which care in the least which name is attached to the enclosures through which they hurry or know anything about a special law of physics that is tied to one mfg.
BUT it is one hell of a smart sales argument, if you want to keep customers “tethered” or “blinkered”.
PPS After TOC’s comment: No, I don’t use Aristo controllers either, I build my own. But the PWM caution regarding the Aristo controllers is well-documented i.e. use linear mode only!
While that is true, it is the combination of supplies and controllers that can create issues (no manufacturer specified).
I know this, as I rebuilt a customer’s Shay that ended up in the front yard, out the front door, as the calling of the local Fire Department was being hotly (!) considered.
An independent (not me, him or the manufacturer of the supply/controller combination) firm did testing and found, if I recall, 36 volt spikes that took out circuits…
So, while the POWER supply may be pure and clean, if the controller of choice is not, thou mayest have issues.
Of course, you will need a good o-scope to actually see some of these…Tektronics 535 springs readily to mind…NOT an OS-8…
Hans-
Thanks very much for the input.
George is diligent in his testing. While he didn’t indicate any problems with the pulse width power coming from the controller, I think Aristo’s assurance via warranty support is worthwhile.
Wendell
Wendell Hanks said:
Hans- Thanks very much for the input.George is diligent in his testing. While he didn’t indicate any problems with the pulse width power coming from the controller, I think Aristo’s assurance via warranty support is worthwhile.
Wendell
Wendell,
I believe you would have to ask them (Aristo), if they cover consequential damages. I’m pretty sure that’s what the term would be, if your LGB or other engine generates more smoke than called for.