hon30critter jjdamnit I don't know if this thread is applicable. Hi jjdamnit, The message that I got from that thread and this one is to stop being lazy and just wire the decoder direct, so that's what I am going to do. Thanks everyone, Cheers!! Dave
jjdamnit I don't know if this thread is applicable.
Hi jjdamnit,
The message that I got from that thread and this one is to stop being lazy and just wire the decoder direct, so that's what I am going to do.
Thanks everyone,
Cheers!!
Dave
That has always been my method. There is not a single component on a DCC ready board that needs to be there for DCC operation. They are just components that could potentially effect how something works. If something doesn't work, I don't want to have to be tracing unnecessary components to find a problem.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
TCS has several Bachmann decoder installation tutorials. C1 and C2 are the offending capacitors and you only need to snio the leads. Inductors don't cause an issue, but capacitors will "smooth" the DCC square wave outout to the motor.
Those that aren't noticng a difference by not doing anything, aren't aware that motor control can be much better than what they're experiencing. The locos will run fine in most circumstances, but will not have the fantastic low speed crawl that's possible with many Spectrum steam locos under "proper" DCC back-emf.
I have never had an issue with their DCC and sound as far as needing to clip anything.
Hello All,
hon30critterThe message that I got from that thread and this one is to stop being lazy and just wire the decoder direct...
All the motors I was dealing with had the chokes soldered directly to them, not on the Original Equipment Manufactures' (OEM) Printed Circuit Boards (PCBs).
I removed the chokes on all the motors, which were easily identified.
With the GP40s the OEM PCBs were removed and the decoders were wired directly to the motor and lights; adding LEDs and the appropriate resistors for them.
Some of the OEM PCBs were DCC while others were "DCC Ready."
With these four (4) locomotives my goal was to standardize the decoders and motors along with upgrading to all LED lighting.
In the GP30s all the OEM PCBs were "DCC Ready" so I was able to use Digitrax 8-pin to 9-pin harness' in the NMRA 8-pin plugs.
They all had LEDs installed and the decoders were standardized to Digitrax.
If the chokes are on the OEM PCB it might be more difficult to identify and remove the relevant ones. In that case, I would wire the decoder directly.
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
hon30critterShould I remove some or all of the three capacitors? If I do remove the capacitors, do I have to put a shunt wire in their place?
The general rule of thumb here is: a capacitor you clip out, an inductor (or choke) you replace with a length of wire (or short permanently, which means the same thing). But you have to be sure 'which is which'. Google "LRC circuit" for an explanation of what the things do.
jjdamnitI don't know if this thread is applicable.
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
I don't know if this thread is applicable.
It deals with the chokes soldered directly to motors on diesel locomotives.
Done with caps & resistors- -Uh...chokes, on motors...
Dave,
I checked the tender setup on mine and L1 +L2 and C1+C2 are still intact with the 8-pin plug in place on the old Digitrax SDH-164 sound decoder. Still works so not quite sure what to tell you.
Scott Sonntag
Interesting thread. In the DCC-ready locos I have, I had to remove a plug which I thought connected these semi-conductors to the motor. I thought that by removing the plug, to plug in the decoder, the procedure would bypass the semi-conductors. I guess I was wrong.
Simon
I agree with eliminating the "RF choke" or whatever they call it. I guess it is a requirement to have the filter for any sales to the EU. DCC people say they wreck havoc with back EMF sensing.
I was lucky with my EM-1 engines that the caps and coils were all on one board making it easy to completely bypass:
Bach_EM1_motor-cap by Edmund, on Flickr
I've come across some that have capacitors soldered directly to the motor contacts.
You should be able to follow the traces of the PC board and jumper right past the caps and coils.
Good Luck, Ed
I have the same locomotive and same setup(different sound decoder, but connected with the 8 pin plug) Let me see what I did.
If there are any capacitors or coils between the motor and decoder, they cause issues with the PWM driving the motor and its BEMF. The caps are usually soldered across the motor terminals (either directly or on the circuit board) and the coils (Chokes/Inductors) are in series.
Looking at the board, I see L1 and L2, those are the coils. Use an ohmmeter to see if they connect to the motor, and if so, you need to short them. Check to see if any component marked "C" also connects to the motor.
RFI Suppression
Hello folks,
I have a Bachmann Spectrum 4-6-0 into which I have installed an ESU Lokpilot decoder. I left the original circuit board in place and plugged the Lokpilot into the eight pin socket. I have read in the past that, in some cases, the decoder will work better if the capacitors are removed.
Should I remove some or all of the three capacitors? If I do remove the capacitors, do I have to put a shunt wire in their place?
Thanks,