zimo decoders

QUOTE (Smokeyone @ 12 Jan 2008, 14:27) <{POST_SNAPBACK}>Is anyone familiar with adding capacitors to zimo decoders so that the loco continues to run over dead track sections.
I understand that it only works with Zimo and not any other make but perhaps someone knows better.

*** if you are competent with a fine soldering iron it can be done to any decoder.

The capacitor plus a diode and a resistor are simply placed after the bridge rectifier on the decoder.

It is not for the faint hearted to do and frankly not necessary if track is well wired and clean and pickup adjustment is done properly on the locomotives. You will need to be able to correctly identify the soldering points too of course. Bear in mind the warranty will be zero if you make an error - I strongly recommend that unless you are VERY good with the soldering Iron you focus on fixing the problem at its source - the pickups and trackwork.

For those who would like to learn more, a good friend has a website which shows a couple of examples - here is the link

http://www.members.optusnet.com.au/mainnorth/alive.htm

Regards

Richard

QUOTE (Richard Johnson @ 12 Jan 2008, 09:21) <{POST_SNAPBACK}>*** if you are competent with a fine soldering iron it can be done to any decoder.

The capacitor plus a diode and a resistor are simply placed after the bridge rectifier on the decoder.

It is not for the faint hearted to do and frankly not necessary if track is well wired and clean and pickup adjustment is done properly on the locomotives. You will need to be able to correctly identify the soldering points too of course. Bear in mind the warranty will be zero if you make an error - I strongly recommend that unless you are VERY good with the soldering Iron you focus on fixing the problem at its source - the pickups and trackwork.

For those who would like to learn more, a good friend has a website which shows a couple of examples - here is the link

http://www.members.optusnet.com.au/mainnorth/alive.htm

Regards

Richard

Thanks very much for the link. Will have a go but will check back on the forum before I switch on the soldering iron.

The Zimo MX63 series decoders have solder pads at the edge of the decoder which are idenitified as being for adding the capacitor circuit. I have done some experimenting using a Hornby Fowler 2-6-4T as the guinea pig because it only has collectors on the six drivers. Richard's point (no pun intended) about getting the collectors and trackwork right is a very valid one but I chose to try the capacitor route because I am not sure that I can fix the other two problem sources I have detected in poor running. These are:

1) I am not convinced that Peco code 75 point work is absolutely flat, so the high spots raise the loco wheels off the track just when the wheel in question is the only one of three with a chance of collecting power.

2) There is no "give" or upward movement in the centre driver of the Fowler with the result that once the centre driver is on a high spot, contact is lost at either front or rear.

I did see an improvement in slow running with 400uF of capacitance but using the 4 x 100uF capacitors which come in the Zimo Speikomp kit takes up too much room to be practical. I have purchased some higher value capacitors which being single units require a smaller volume but is still a bit on the large side.

The "correct" solution would be to have pointwork that is flat and a centre driver which is capable of "floating" in the vertical direction.

I am considering building my own track because I am no longer happy with the appearance of the Peco and I find the geometry on offer restrictive. If I am able to manage this then the pointwork problem should go away.

I do not feel competent to mess about with the Fowler chassis but maybe one day....

David

***Dead right in both memories David.
(a) there are none with it fitted "ex the packet" and ( Its the lenz UPS and is as you say expensive

- it works fine but it also requires good soldering skills - I've seen about a dozen decoders destroyed by owners trying to attach it with indifferent soldering tools & skills!

Richard

QUOTE How about the Zimo MX64 decoders.The blurb says, "engine won't stall on power interruption of up to 1 sec. (e.g. dirty track)"

Could you provide a URL for that quote please? The MX620, MX63 and MX64 share the same manual. I have checked the english language PDF on the Zimo website (on line Zimo MX620, MX63, MX64 manual) and using "dirty" as the search key only turned up the following section:-

QUOTE Smart stop management MX620, MX64D, MX64P with first SW version; with SW version 25 for MX62, MX63 and MX64
Operational only if power is provided by an external energy source (MXSPEIG or condenser with at least 1000uF)!
If the decoder looses power while the engine is coming to a stop (dirty track, non-powered frogs etc), it en-sures that the engine continues until power to the decoder is restored. Once power is restored, the engine is allowed to stop. With the engine at a standstill, the decoder again checks for track power and if neces-sary moves the engine a bit further.

The diagrams for attaching external capacitors include one for the MX64 as well.

I don't use the MX64 because it is larger than the MX63 and until the quote you posted, I didn't think it offered any extra feature I might be interested in. If they have got a built in storage capacitor then I really would be interested which is why I would like to see the original source for your quote.

However, I have to say that I am sceptical about it being possible at OO/HO scale in a reasonable size. The manual states you need at least 1000uF. I have tried 400uF and the effect is only just starting to kick in at that level. 500uF and 1000uF capacitors capable of withstanding typical DCC voltage with a little margin - usually a 25 volt rating for OO/HO - are too large to be accommodated in the extra few millimeters offered by the MX64. The Lenz Gold USP addon has a reasonable volume too though it is more of a rectangular shape which may provide more options for fitting. DIY solutions like the Zimo option use cylindrical capacitors which means there is no slim dimension.

I should qualify my remarks by saying that I am looking at these solutions from a UK steam point of view. Whilst they can probably be accommodated in the tender of a locomotive relatively easily, you can improve tender locos with extra pickups on the tender (hello? is any one at Bachmann readiing this). The real problems are with small 0-6-0 tanks. Diesel / Electric users should have a much easier time of it.

David

QUOTE Here's the URL http://www.mrsonline.net/html/decoders.html Look about half way down the page under 'features'.
You are absolutely correct , but when you follow the "full features" link you find this

QUOTE Uninterrupted driving on dirty track with external energy buffer, MX63, MX64 and MX69

As much as I want the MX64 to have the built in energy buffer, I think the fact that there are slightly different stories in the mrsonline site indicates that the energy buffer is indeed external

David