Bachmann Controller

[mukyz1]

I am having issues with the power pack for my layout product code 44212.  The trim pot is playing up, for example when I gradually turn the knob the train starts off fine, turn the knob a little more and train suddenly hits maximum speed..  Not good.  Turn the switch down and it is very erratic at low settings.  What I would like to know is where I can get a new trim pot and switch? 

Is this possible?  I am guessing I am up for a new controller.     

[jbrock27]

More than likely, it is new controller time.  Is this DC?  How old?  If replacing, I recommend any currently made MRC DC power pack.

For a new pot, try Mouser.com.  But you need to know the specs on the one you are tyring to replace.  What kind of screws hold your power pack together?  Are they the tamper proof kind?

[mukyz1]

Hi there, yes its a DC controller and it has Phillips screws.  I have taken a look at the combo trim pot and switch mechanism but no details on it.  I believe all I need do is replace it.   I will try mouser.com.  cheers.

[richg]

Hi there, yes its a DC controller and it has Phillips screws.  I have taken a look at the combo trim pot and switch mechanism but no details on it.  I believe all I need do is replace it.   I will try mouser.com.  cheers.

Is the device an actual potentiometer?
I have photos of the older Bachmann power pack that is black plastic case with a red knob. The speed control was a multi tap transformer with each tap brought out on a PC bard. The knob had a pointer that would pick up each tap on the PC board for more or less voltage.
No potentiometer.
I do know the Powers That Be here do not want any photos of the inside posted here.

Many power packs have used a low wattage pot connected to a power transistor for DC. Been quite a few years since I have been into a MRC power pack.

Rich

[mukyz1]

It is a newer type with a trim pot and switch combination.  I have since tried tuner cleaner which has resolved the issue.  Thanks everyone for your assistance.

[richg]

It is a newer type with a trim pot and switch combination.  I have since tried tuner cleaner which has resolved the issue.  Thanks everyone for your assistance.

Good to know that there is actually a potentiometer. Some power packs use a rather low quality potentiometer which many times is the issue with power packs.

The power packs I made used a quality 10 k sealed potentiometer.

Usually I use tuner cleaner or CRC2-26 which many use for improving pickup on track.

Rich

[jbrock27]

Excellent!!