The output of a power pack changes polarity when you reverse the loco even if you bring the loco to a gradual stop. Put a DC meter on the connection and see what happens. Hang a capacitor at that point which was suggested and you reverse the voltage to the cap. Poof. You want pure DC to power a dual more decoder, thus no AC or pulse power. Some more expensive DC power packs actually have square wave pulse power. I have had one. Dual mode decoders get confused by pulse power as the decoder microprocessor is looking for pure DC or DCC pulses. This has happened to some people using DC and dual mode decoders. I belong to a bunch of MRR forums and have seen this issue before. Rich
Although I was not clear in my first post, I was not suggesting you place a single capacitor at that point, if you place two capacitors in series across the terminals, with the capacitors '+' to '+' or '-' to '-' then it will work with no fear of blown caps.
Bachmann 1o wheeler The post explaining why the engine hesitates on dc is a correct response. If you have bad track connections the engine can't maintain a steady drive to the electronics. Since it takes a minimum starting voltage to begin moving when that power is interrupted there is a delay time for the decoder to start pulsing to the motor again. No amount of capacitor filtering to the output will correct this. Some decoders have a larger storage capacitor to compensate for dirty trackwork or wheels. Modifications of this sort are best left to experts. Allan Borg
I made the comment because there are modelers who will do what “seems” to be suggested or will tell someone the same thing. I have put electrolytic capacitors back to back when I did not have the appropriate bi-polar capacitors. Many bi-polar capacitors are usually not a large enough micro-farad value for power supply filtering. Rich
For those of you who like turning your stub tracks off with DPDT switches I might have a solution that may have been forgotten about. as a father of a challenged son I cannot rely on him to turn the power off the storage tracks using switches . So what I have done is extended the powered frog rail out to the end of the track/s. When I want to control-- on/off-- I throw the turnout aganst the track in question and this sets up the tracks to make both rails +-+ and the other track neg-neg or when I throw it back---basicaly the engines (see ground or open circuit) at track potential. The nice part is no toggle to throw and little to nothing to remember,at this point its mostly automatic if you have traffic running thru the continuning part of the turnout. If you want just to have one dead track just leave the frog the normal lengh for the continuning track. Hope the helps ~AlanC.
Gosh guys, I truly appreciate all your replys..I believe Robert CSX has hit my exact problem. I hate to admit it, but what are 'caps' ? If they are some type of capacitor please let me know the value or whatever specs it should be and where to wire into my MRC Tech II. Can I buy it at Radio Shack and just solder it in to MRC circuit ? In the end though I really believe I simply need to change to a digital throttle to end all this hassle, huh ? Thanks again for all the advice. And yes, I SHOULD have started a new thread instead of sidetracking this one..Sorry about that ....MH
Caps are short for capacitors. I thought that would be obvious. Exactly what are you attempting to do or want to do? I suspect you do not know. Spell out exactly what you would like. We are still in a guessing game until you do. Rich
I hear adding a CAP to my analog MRC Tech II power pack will make my dual-mode Bachmann Tsunami 10 Wheeler cease its jerky roll-offs. I can't creep start and believe it to be somthing with the pack needing a cap added. So, if you or anyone knows, were in circuit does it go ? I'd guess it's in the output stage..Any dibbs ? Mark in LA...
