Hi everyone!
I am working on a Mack 15 ton switcher engine kit. The body is from Jordan and I am using a powered truck from an older Bachmann 44 tonner as motive power as per Darth Santa Fe's original idea.
I have the power truck running OK but it is very sensitive to power interuptions. Yes, the track is very clean. The body has a fair bit of added weight in the form of lead sheet. Test runs without the body revealed frequent stalling. Test runs with the body in place reduced the tendancy to stall but did not eliminate the problem completely.
My question is about installing capacitors to keep the motor alive during the brief power interuptions. I would like to know what size would be effective, and I would like to know exactly where in the circuit to install them. There is no sound (I wish there could be but there simply isn't space for a speaker.) Space is at a premium but I have about 1/2" x 3/8" x 1/4" still available in the upper part of the cab.
Here is a picture with the body off. If you look into the lower sides of the cab you can see where the lead weight has been installed:
Here is a picture with the body loosley installed. Sorry about the focus. You can see that there isn't a whole lot of space for big capacitors. The wires sticking out the top are for the headlight/tail lights.
Any suggestions about capacitors?
Thanks as always.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Dave,
Anything that I'm aware of,you would have to have a trailer,to put it in,,,,hopefully there is,some circuit,that is small enough to fit,,,,that's little!!!
Have fun!!!!
Cheers,
Frank
Hi Frank:
I have some SMD 0603 capacitors that are rated at 100pf. My problem is that I don't understand capacitor ratings so 100pf does't mean much, but I am assuming that they are pretty small. I am wondering if it would be possible to wire a number of these small capacitors into a larger 'block' (for lack of a better word), and get anything useful out of them? How much 'capacitance'( is that the right word? ) would I need to bridge momentary interuptions in power for a non sound motor?
I know that TCS has a capacitor power interuption device available but there is no way that it will fit in the 15 tonner, and I am trying to avoid using a 'trailer' as you suggested. I also don't think I need several seconds of alternative power supply. One second would seem to be more than adequate given the current performance of the engine as long as the recharge time is fairly quick.
By the way, if anyone could enlighten me on capacitor ratings and relative functionality, that would be very much appreciated! I used to love running my boat in the dark, but that was when I knew where I was going and I could see the horizon!.
EDIT: It didn't take me too long to figure out that the 100pf capacitors would be rather useless in this installation once I read the posts.
You would need a Polarity sensitive,Electrolytic,capacitor,and other components,to do what you are asking and I am rusty on that.. Check out ,Elect.and DCC,Forum,on Rad Lite LED Lites for passenger cars and read the Lion's, post...That should help you....
Thanks Frank
I checked out the Lion's post and came to the conclusion that the solution to my problem may not come easily, if at all.
That however, is not going to stop me from investigating further. Good thing my back surgeon said I had really solid bones! I can afford to bang my head that much harder!!
I forgot to mention,,being the room,you have available in that little mouse,,,that is going to be the tough one...
Ya, I am beginning to realize that this may not be possible without a trailer as you suggested.
However, I ain't quitting just yet! Just have to put my thinking cap on, that is if I can find it!
Thanks a bunch for your help. Edit: see my post about banging my head above!
Who knows,the way,the Electronic's Software industry is growing,these day's,,they may come up with a NANO,circuit,that will provide,what you need...
Talk To You,,
Look at the Train Control Systems web site -- they have a "keep alive" module that can be added to an existing decoder.
http://www.tcsdcc.com/
CACOLE,
Do you think they will fit in that mouse,he has though??
Check the dimensions of the stay alive decoder at the TCS website. Most online DCC stores show the specs also.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
TCS offers decoders with the "keep alive" built in. They're the same size as a regular HO non-sound decoder. The "keep alive" add-on only works with TCS decoders that have a place to plug-in the add-on.
If you can find the room, go for the TCS. I had a first-run Proto 0-8-0 that came with no power pickup from the tender wheels, and it ran so poorly I never used it. I put a TCS "keep alive" in it, and now it runs great.
I have looked at all the TCS offerings, both for the add-on circuit and for the decoders that have the Keep Alive built in. They are all too large to install in the switcher itself.
I do have a TCS Z2 decoder on order which is supposed to be pretty small. It is intended for another project but when I get it I will see if using one in the 15 tonner will give me any more space. The TCS Z2 does not have the Keep Alive function. I am using a Digitrax DN135 right now.
I have the option of removing some of the weights to make space but that seems to be totally counter productive. Even then, there is only 7/16" from the front to the back of the cab. All of the TCS circuits are larger than that. Even if I put them on their sides they still won't fit.
You won't get any "stay alive" capacity from any single capacitor that will physically fit that little guy.
For a single capacitor, you need at least a 16 volt rating and at least 100,000 microfarads to get a second or two stay alive ability - plus a resistor and diode .... which won't even come close to fitting. The TCS modules have one farad of capacitance (one million microfarads) but use multiple 2.5 volt capacitors in series to get the size down.
Instead of the drive you used, you could have used one of NWSL / Stanton drives and had both hoods and the cab wide open which would have given you plenty of room for a decoder and stay alive module ....
http://www.nwsl.com/uploads/cat_chap2_for_web_3-01-13.pdf
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Hi Mark:
Thanks for the information about what capacitance I would need to get a reasonable amount of reserve power to keep the critter operating.
I looked at the NWSL Stanton drives and their model 1210 does offer the correct 6' 6" wheelbase. Unfortunately the width of the Stanton drive's body is just a bit too wide to fit inside the 15 tonner's body. It is very close but in order to get the wheels at the right height the Stanton motor has to go up into the shell a bit, and it is too wide for that. I could mount the body higher above the wheels I guess. I would have to do a mock up to see if the switcher still looked reasonably accurate.
There is another small issue and that is the price of the NWSL Stanton drives. I got the powered truck I am using for about $10.00 and I have eight of them to work with. (I bought four of the Bachmann 44 toners with the two motor drive through eBay for about $20 per engine). So, being a (something that starts with a B) for punishment, I have committed myself to working with the 44 tonner self powered trucks.
My next step is to see what size capacitors I can gang together to accomplish basically the same thing the TCS 2.5 volt capacitors do. Maybe I can, and maybe I can't, but I ain't quitting just yet!
Thanks for your help!
OK! I give up!!
I just spent a bunch of time searching Digi-Key's site for capacitors that would do the job AND fit, and as Mark gently suggested, there ain't no such thing!!
Oh well, now I have to explore other options. The concept of a trailer is becoming more interesting, or perhaps two 15 ton Macks hitched together with one powered and the other carrying a TCS Keep Alive decoder.
I'm going to have to think about this one a bit more.
Thanks for all of your input!
As I said in the beginning,,trying to get something to fit in that little,mouse,is going to be the tuff part..When I mentioned trailer,,,How about,the mouses,sister,a little work caboose,behind her brother?? Just a thought!! Don't give up,''Buddy'', I have confidence,in you..
zstripe Dave, As I said in the beginning,,trying to get something to fit in that little,mouse,is going to be the tuff part..When I mentioned trailer,,,How about,the mouses,sister,a little work caboose,behind her brother?? Just a thought!! Don't give up,''Buddy'', I have confidence,in you.. Cheers, Frank
You can even,have,elect. pick-ups,on the mouse,caboose..
If you run two of them together, you might not even need the keep alive, as you would then have 8 wheel pickup. But that's pretty much the only option, even the smallest surface mount capacitors aren't going to be of sufficient value to give any effective keep alive ability when also small enough to physically fit. You could give it a try, wutht he highest value 16V rated surface mount capacitor that will fit - the resistor and diode aren't strictly needed, although you may have trouble programming it with just the capacitor. It may only give a fraction of a second of juice but that may be enough to keep it moving.
The only other option is to make sure all frogs are powered, and keep everything scrupulously clean - track, wheels, pickup wipers.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I think you are going to have trouble running it if you filter that track signal too much. The decoder relies on the pulse width modulation that is DCC. The modulating DCC square wave peaks from plus to minus at about 5 -10 KHz. I'm not sure about that freq range, but I don't think that you can put enough C on it to improve power pickup without "rounding off" that signal too much. The Booster may not like it, either. I think you need a special "keep alive" circuit designed for the DCC signal.
DC
http://uphonation.com
dcfixer I think you are going to have trouble running it if you filter that track signal too much. The decoder relies on the pulse width modulation that is DCC. The modulating DCC square wave peaks from plus to minus at about 5 -10 KHz. I'm not sure about that freq range, but I don't think that you can put enough C on it to improve power pickup without "rounding off" that signal too much. The Booster may not like it, either. I think you need a special "keep alive" circuit designed for the DCC signal.
The capacitor installs in parallel to the rectified input on the decoder and does not affect the overlayed signal what-so-ever. All it does is to continue to power the board after track contact is lost. The internal memory in the chipset will maintain the last signal received before power loss - there are no signal packets being received during a power loss.
Randy:
Two 15 tonners working together would look pretty neat in my opinion. I can see that if both were motored and there were power connections between the two engines running reliability should be pretty good. I will have to do an amp test to see if I could get away with running two motors on one decoder. If not its no big deal. I would have to speed match the two engines as well as possible.
Frank:
I have a gon behind the critter in my avatar which actually contains the motor, so I'm not averse to using a gon to carry a Keep Alive circuit. I could also wire the gon for power pickup which would theoretically make the consist a very reliable runner. By the way, my avatar critter has - get this - 12 wheel pick up! Four on the engine wheels and eight on the gon. The gon has four wheel trucks because it was originally an N scale coal tender.
Mark:
Even if the capacitor did not interfere with the DCC signal I still have to find space for it. That clearly isn't going to happen in the 15 tonner if it runs by itself, but thanks for your input.
Everyone! Thanks for your help. There seems to be two choices - run two engines together, or hook up a gon or caboose to carry the Keep Alive circuit. I have enough kits and power trucks to do both actually, so I might just do that! I'll have critters running everywhere! May not leave any space for real trains!
You wouldn't have to put a motor in the second one - just some weight and pickups. Oh and a keep alive capacitor. In fact there might be enough room for a keep alive capacitor and a speaker - with a Loksound Micro in the powered unit.
OK Randy!!! Enough already!!! How dare you spend my money like that!!!!!
Seriously, good idea re the sound. Do you happen to know if Loksound has an appropriate engine sound available? I looked into sound for my mini-goose but I couldn't find anything suitable on the market. Loksound has a Gallopping Goose sound decoder in the works but they don't seem to offer an availability date. It is possible to add your own sounds to a Loksound decoder but unfortunately for me at my current stage in electronic modeling, that seems to be a bit out of my reach.
EDIT: The Loksound micro will actually just fit into the 15 tonner cab! OK, now things are beginning to take shape! I now have to research their available sound files to see if there is anything that would even remotely sound like a Mack engine.
I put a Loksound micro decoder, speaker, headlights / tail lights AND a stay alive module in a powered hi-rail truck .... so it is possible !
Loksound has some great small diesel sounds in their European section. I found a perfect one that sounded just like a diesel truck - even had the correct starter sound !
Hi Mark
I spent some time tonight listening to Loksound's available selections for their micro decoder, and there are indeed a couple that would work just fine. I am not a rivet counter so the differences between a small diesel and a small gas engine aren't going to cause me to lose any sleep.
By the way, I am assuming that the Mack 15 tonner was gas powered. I hope I am right on that but if not, somebody please kick my ........ OH, sorry, not to offend the moderators....... kick my shin!
Mark R. The capacitor installs in parallel to the rectified input on the decoder and does not affect the overlayed signal what-so-ever. All it does is to continue to power the board after track contact is lost. The internal memory in the chipset will maintain the last signal received before power loss - there are no signal packets being received during a power loss. Mark.
That's makes sense. I misunderstood where the capacitance would be added. Does it require soldering on the decoder, or is there some kind of plug provided?
The Goose one would probably be the closest to a small gas engine. They do have one for the V4 series that's a VW "Bus" but the 4 clylinder opposed VW motors are very distinctive sounding and anyone that's ever heard one will immediately recognize it. The V4 Micro is probably the best bet, over the Select Micro, since you cna easily mix and match sounds to get a decent motor mixed with a plausible whistle or some sort (I'm sure those little switchers didn;t have some big K5LA on them! Probably a single chime air whistle, not even a simple honker air horn). Of course, you'd need a Lokprogrammer to edit the sounds.
DCFIXER - this generally requires soldering on tot he decoder but thew latest TCS T series decoders have a plug to attach the keep-alive, and some others bring the required connection out to regular connection tabs on the decoder, same as things like track pickup wires and headlight wires attach, the new Loksound decoders are like that. The wire 'missing' on most motor decoders is a negative common off the rectifier, usually you have to go under the shrink wrap, if present, and attach a wire to the approriate spot on the decoder board. The blue headlight common is the positive side.
A Stay Alive link everyone should read and store in Favorites or Bookmarks. Helps prevent assumptions. A lot of this is experimenting.
http://www.members.optusnet.com.au/mainnorth/alive.htm
Pay attention to the resistor and diode. Many who assume are not aware of this.
Marcus is very active in some of the Yahoo DCC Groups.
If you need say, 1000 to 2000 ufd for caps, they will take up some room.
Some sound decoders come with 250 ufd but only for sound.
Rich:
Thanks for the link to Marcus's information.