PWM whine advice?

H

Highball18

I'm New, Please Be Gentle
Country flag
Just picked up an old Aristo Craft set (RC Cola Taste Express) with the basic PWM controller. It’s nice to have more consistent lighting brightness and better smoke unit performance, but the high pitched whine of the motor on PWM drives me crazy. The locomotive runs quiet on a straight DC supply but the lights are significantly less bright and the (admittedly cheesy) steam chuffing sounds don’t work on straight DC (It must be generating the static sound from the PWM?). Is there a simple way to tame the whine without loosing the benefits of brighter lighting and better smoke?

Thanks for your thoughts!
 
Greg Elmassian suggested this device might work for my DUO switching locomotive.

s121332513913518739_p102_i2_w640.jpeg

See this thread; LGB DUO SYSTEM SHUNTING LOCOMOTIVE QUESTION

I was going to post the question as to how to insert it into my system. Perhaps we may be able to get some more info from our learned members for both of us.
 
Dan,
The PWM filter turns the Peaky PWM to smoothed DC. - So produces a variable DC voltage.

This might help you with the Duo system, but will not help the OP with his 'whine' problem, as he wants the full-brightness of his lamps.

The basic Aristocraft system may well produce a constant 'chuff' tied to the mains frequency.
So using 'smoothed' DC won't help with that either.

Swapping the filament bulbs (for warm-white LEDs) will give full brightness from very little voltage, but will require some soldering and knowledge to calculate limiting resistor values. - Also remembering that LEDs are polarity sensitive.

The only other way to lose the 'whine' is to replace the PWM controller with a new high frequency one.

The website of someone no longer on the Forum, has some information on the Aristocraft equipment.

PhilP
 
PhilP said:
Dan,
The PWM filter turns the Peaky PWM to smoothed DC. - So produces a variable DC voltage.

This might help you with the Duo system, but will not help the OP with his 'whine' problem, as he wants the full-brightness of his lamps.

The basic Aristocraft system may well produce a constant 'chuff' tied to the mains frequency.
So using 'smoothed' DC won't help with that either.

Swapping the filament bulbs (for warm-white LEDs) will give full brightness from very little voltage, but will require some soldering and knowledge to calculate limiting resistor values. - Also remembering that LEDs are polarity sensitive.

The only other way to lose the 'whine' is to replace the PWM controller with a new high frequency one.

The website of someone no longer on the Forum, has some information on the Aristocraft equipment.

PhilP
Click to expand...
Philip correct me if I'm wrong surely he just needs to insert that device in line with the motor and leave everything else on the existing system because it's only the motor that's causing him the issue so if you just cut the motor feed put the motor feed into that and then back out, that should work????
 
Madman said:
Greg Elmassian suggested this device might work for my DUO switching locomotive.

View attachment 314770

See this thread; LGB DUO SYSTEM SHUNTING LOCOMOTIVE QUESTION

I was going to post the question as to how to insert it into my system. Perhaps we may be able to get some more info from our learned members for both of us.
Click to expand...
I have one of those on the output of my Revolution trackside throttle. It works well for my purposes, but I'm not that worried about lights. as my railway shuts down before sunset :snooze:. Running in the dusk might be fun were it not for the gottverdammte skeeters :swear:.
The old 199-something Train Engineer trackside throttles on my Thomas layout have a PWM/DC switch on the output. I had them on PWM for a while then switched to straight DC as the PWM didn't seem to work any better and I didn't want to risk mucking up any fancy cards in the lokies. I know the risk is infinitesimal, but that's me :p.
 
wandgrudd said:
Philip correct me if I'm wrong surely he just needs to insert that device in line with the motor and leave everything else on the existing system because it's only the motor that's causing him the issue so if you just cut the motor feed put the motor feed into that and then back out, that should work????
Click to expand...
The device pictured is probably too big to fit in most locomotives. I don't know if smaller ones are available.
 
wandgrudd said:
Philip correct me if I'm wrong surely he just needs to insert that device in line with the motor and leave everything else on the existing system because it's only the motor that's causing him the issue so if you just cut the motor feed put the motor feed into that and then back out, that should work????
Click to expand...
Nice bit of lateral thinking..

Yes, that should work for the OP.
But it will require one per loco, and there may be an issue of finding space?

PhilP
 
If someone wants advice on wine, can I suggest a Spanish Rioja or an Argentinian Malbec? if it's white that you're after, look no further than Chile. :nerd::nerd::nerd:
 
Chris Vernell said:
The device pictured is probably too big to fit in most locomotives. I don't know if smaller ones are available.
Click to expand...

Fortunately, my RAILBOSS system and battery are in a trailing car, so room isn't an issue.
 
Last edited:
Thanks for all the replies!!

I’m thinking this might be a whole lot of work just to use an old controller. I don’t intend to use the smoke much if at all, and I’m thinking the whine is far more bothersome to me than dim lights. The engine seems to run just as smoothly on an LGB starter set transformer as it does on the Aristo unit. Seems that the best option for me at this time is to just use the LGB transformer to run my trains…
 
Madman said:
Greg Elmassian suggested this device might work for my DUO switching locomotive.

View attachment 314770

See this thread; LGB DUO SYSTEM SHUNTING LOCOMOTIVE QUESTION

I was going to post the question as to how to insert it into my system. Perhaps we may be able to get some more info from our learned members for both of us.
Click to expand...
That device has a plus and minus on the output. Unless the electrolytic capacitors are bi-polar they will not appreciate being fed in reverse when you reverse the loco. To quote Jameco Electronics "The destruction of electrolytic capacitors can have catastrophic consequences such as a fire or an explosion." You can only use this if your reversing switch is between the device and the motor.
 
When using 2 capacitors of 25 WVDC or more (working volts direct current) installing them back to back (minus to minus and separate plus leads to each rail and will not cause an issue. This is what Aristocraft did and added a high frequwncy filter with a resistor anc capacitor plus a choke coil to one power supply lead. Thes ehave worked for years.
 
Dan said:
When using 2 capacitors of 25 WVDC or more (working volts direct current) installing them back to back (minus to minus and separate plus leads to each rail and will not cause an issue. This is what Aristocraft did and added a high frequwncy filter with a resistor anc capacitor plus a choke coil to one power supply lead. Thes ehave worked for years.
Click to expand...
Thanks for the clarification.
 
sgcox said:
That device has a plus and minus on the output. Unless the electrolytic capacitors are bi-polar they will not appreciate being fed in reverse when you reverse the loco. To quote Jameco Electronics "The destruction of electrolytic capacitors can have catastrophic consequences such as a fire or an explosion." You can only use this if your reversing switch is between the device and the motor.
Click to expand...

So it seems there is more to my problem than first thoughts.
 
Dan, in case you didn't catch the comment in post #14:

The filter can be used with either polarity.
But, if you are fitting it in 'something' where the polarity is important, then the annotation on the board, allows you to know the polarity into (and out of) the device.

PhilP
 
Dan said:
When using 2 capacitors of 25 WVDC or more (working volts direct current) installing them back to back (minus to minus and separate plus leads to each rail and will not cause an issue. This is what Aristocraft did and added a high frequwncy filter with a resistor anc capacitor plus a choke coil to one power supply lead. Thes ehave worked for years.
Click to expand...

Dan, could you be more specific ? Given the device we are discussing, how would your suggestion fit in ?

484362_s121332513913518739_p102_i2_w640.jpeg
 
You must log in or register to reply here.
Back
Top Bottom