Jump to content

Sir TophamHatt

Zimo Decoder Questions

Recommended Posts

Quick question:

What 8-pin decoders do Zimo produce that can accept Stay Alive?

Turns out it'll be the MX633 for a start.

 

I have a few locos that have the MX621 and some have MX600 but that's only because I didn't know the difference between them!

 

Is there a simple list of what decoders have what features/pins/whatever?

I looked in the manual but it's still a little clunky to understand. Perhaps I should re-write it, take out all the extra info that isn't really needed, as I guess then I'll get to know the decoders and their features!

Managed to understand the manual as far as I need.

Although it's still confusing. The MX600 doesn't say it has reduced features, compared with the MX622, which states it has full features. So does it have reduced or full features - whatever that means?!

 

For my own remembering:

MX600/MX600R: 4 functions

MX621/MX621R: 2 functions, reduced features

MX622/MX622R: 2 functions (plus 2 function "ready pads), full Zimo features.

MX623/MX623R: 2 functions (plus 4 "ready" pads).

MX630/MX630R: 4 functions (plus 2 "ready" pads).

MX633/MX633R: 4 functions (plus 6 "ready" pads), stay alive capable.

Edited by Sir TophamHatt

Share this post


Link to post
Share on other sites
 
 

The one I use is MX645 used with stay alive but I am sure there will be other Zimo decoders..

Edited by michaelp

Share this post


Link to post
Share on other sites

On the MX600 and also on the MX612 you have to solder the ground cable on a position on the chip - but the position is clearly described in the manual. I did do it for all my MX600 (and those are 10 if I am nor wrong - as they are cheap :sungum: ). I never did it on a 621, which is a bit smaller. In any case to do so you need a very fine soldering iron (I use 6 Watt), a fine solder wire (preferably 0.5mm) and if you do not have perfect eyesight also a magnifying glass or an optivisor (what I do, as then I have hands free....)

The shrink foil cover on the chip has to be partially removed, and after soldering I normally seal the soldering point with a drop of hotmelt so that the soldering doesn't see mechanical threats if the wire is moved.

 

I didn't ruin a single chip so far and all my stay alive locos run fine.

 

I suppose you have downloaded the Zimo manual - if not find it here. http://www.zimo.at/web2010/documents/MX-KleineDecoder_E.pdf see page 6

 

And finally: good luck!

Edited by Vecchio

Share this post


Link to post
Share on other sites

does this mean i can add stay alive caps to my mx600R's ??????

 

 

 

have you got any pictures?

 

Yes you can.

I can send you a picture in the evening (company computer doesn't like flickr....)

Share this post


Link to post
Share on other sites

that would be fantastic.

 

what size caps do you use? how do they actually attach....

 

the manual on page 7 says "makeshift ground terminal if required between the diodes and the capacitor"... so the negative goes where, what about the positive leg ???

 

I have a load of 50v 100uf ones lying around.

Edited by ianjeffery

Share this post


Link to post
Share on other sites

The positive is the blue wire. (don't ask me why, but this is standardised on all decoders)

100uF will be a little low to see an effect. I normally use 1000uF or 1500uF and if there is space enough I even put some in parallel to increase capacity. Old Lima's were a perfect place for stay alives - first they really need it because of bad performance, second there is enough space above the dummy bogie.

Try to find 25V types on the internet, for instance at Conrad (called Rapid electronics here on the island.). Look carefully at the size, there are quite some differences.

for instance 1000uF radial 25V 10x21mm 16pence (min quantity 5). For my experience it is easier to find space for 2 with 10mm diameter than for one with 14 or 16mm diameter.

 

By the way - no space for capacitors? See what I did 15 years ago... This was an Austrian page, but no fear it is in 2 languages...This was with a Zimo MX63 - this decoder model is long time gone and replaced by others. But my loco with the MX63 runs today like on the first day. Hats off to Zimo.  

http://atw.huebsch.at/modell/h0/LIMA_2061_V20.htm

Edited by Vecchio

Share this post


Link to post
Share on other sites

Thanks.

 

Although it's still not entirely clear where to put the blue or black wire from the stay alive :P

I'll have to zoom in a little.

 

Could you also draw out (simply) how to daisy chain some together?

Edited by Sir TophamHatt

Share this post


Link to post
Share on other sites

To increase the capacity you have to connect the capacitors in parallel. Means you connect all the + poles together and all the - poles together. Doing so you just have to add up the capacities to get to your new total value.  

Ctotal = C1 + C2 + Cn

Example: 3 x 1000uF 25v = 3000uF. The maximum voltage stays unchanged at 25Volt

 

 

 

If you connect capacitors in series you will decrease the capacity but increase the maximum operating voltage

 

the capacity will be: 1/Ctotal= 1/C1 + 1/C2 + 1/Cand the voltage will be Utotal =U1 +U2 +Un

Example: 3 capacitors of 1000uF 25V in series

1/Ctotal = 1/1000 + 1/1000 + 1/1000 = 1/0.003 = 333uF

Utotal = 25 + 25 + 25 = 75Volt

 

This will be used in case of supercaps which have a rather low maximum voltage.

 

Blue and black wire on Zimo decoders with stay alive circuit built in: also for the stay alive capacitor blue is plus and has therefore to be connected with the plus pole of the capacitor and black is ground.  

 

Drawings / pictures come later.

  • Like 1

Share this post


Link to post
Share on other sites

The positive is the blue wire. (don't ask me why, but this is standardised on all decoders)

100uF will be a little low to see an effect. I normally use 1000uF or 1500uF and if there is space enough I even put some in parallel to increase capacity. Old Lima's were a perfect place for stay alives - first they really need it because of bad performance, second there is enough space above the dummy bogie.

Try to find 25V types on the internet, for instance at Conrad (called Rapid electronics here on the island.). Look carefully at the size, there are quite some differences.

for instance 1000uF radial 25V 10x21mm 16pence (min quantity 5). For my experience it is easier to find space for 2 with 10mm diameter than for one with 14 or 16mm diameter.

 

By the way - no space for capacitors? See what I did 15 years ago... This was an Austrian page, but no fear it is in 2 languages...This was with a Zimo MX63 - this decoder model is long time gone and replaced by others. But my loco with the MX63 runs today like on the first day. Hats off to Zimo.  

http://atw.huebsch.at/modell/h0/LIMA_2061_V20.htm

 

so the negative lead goes to the two small pads on the chip, and the positive connects to the positive blue wire ?

 

ok, that sounds easy.

Share this post


Link to post
Share on other sites

Yes it is not complicated, but, especially for bigger capacitors, you need a resistor to limit the charging current, otherwise your DCC controller will tell you "short circuit"

This resistor is rather a low value, you want to limit to a current the decoder can easily handle. Zimo recommends 33Ohm for capacitors up to 2200uF or 68Ohm for bigger capacitors. In the latter case you need also a diode so that the energy from the capacitor goes to your decoder without being limited by the resistor. See page 60 of the manual (liknk further up this thread)

 

So here are some pictures: 

First 3 already modified decoders as described before.

 

43335312155_cfab1f0744_b.jpg20180824_171357 

 

Now the position for the ground connection. Note that the shrink foil is already removed. Sorry for the picture quality - I was to lazy to get a proper camera out. This is all what my rather dated Samsung can offer....

 

43523591114_a175d3503f_b.jpg20180824_172034 

 

 

Now how to connect capacitors together: 

First 2 1000uF capacitors parallel to get 2000uF. This is just for the picture - please consider insulation tubes to avoid short circuits. Especially in larger capacitors there is quite a bit of energy. So better no short circuits....

30373791238_b8876437a2_b.jpg20180824_172836 

 

Now a few in series (these are supercaps) 

43523589824_960eb08c14_b.jpg20180824_172321 

 

And we spoke in another thread of Sir Topham Hatt about soldering - this is what I use for fine stuff. Contains lead and is only 0.5mm. Flux is inside the wire. 

 

30373791928_9e1a571f0c_b.jpg20180824_172640 

 

So keep all the naughty trucks well sorted in the yard and happy soldering!

Share this post


Link to post
Share on other sites

Not today. Probably after the weekend. Social program starting....

  • Like 1

Share this post


Link to post
Share on other sites

is it between the two small diodes at the side of the board?

 

Yes it is. To get this sorted I need to go for some serious kit...

29449788877_0c0f91232a_b.jpg20180831_090538 

 

First the decoder as it is and the position marked by a pin. 

 

29449751137_7ef584aa23_b.jpgDSC_0076 

 

Next I cut a window into the shrink sleeve

 

29449740527_a41de6fa14_b.jpgDSC_0086 

 

Even I did this with a new scalpel blade it doesn't look nice under this magnification.

 

Now comes the soldering. 

42577715750_5547a4109f_b.jpgDSC_0089 

 

And now sealed with hotmelt glue.

 

29449758417_afa19368bd_b.jpgDSC_0093 

 

As mentioned if you use a larger capacitor (or a few small ones in series) you need to limit the charging current. On the other hand you want full power when needed. So you need a resistor to limit the current and a diode to allow discharge without the resistor. I use 47 Ohm (could be a bit larger, but this is what I have) which limits the current to 340mA (at 16V). With this the control station has no problem and there will be no short circuit detected. The diode is 1N4007, a 1Ampere type. 

 

44386173691_2307b51021_b.jpgDSC_0090 

 

To avoid short circuits I pack the arrangement into a shrink tube. 

 

29449754457_1512809336_b.jpgDSC_0094 

 

So. Now the whole thing need to go into a loco. I have one on order, it is a tiny permanent way "draisine" (light auxiliary rail vehicle for crew and material transport)

Because of it's size it will need a stay alive. Will see how it goes. Small picture of the X 626 below. 

 

44338099422_c59359f8f6_z.jpgliliput X 626 

 

Hope this was of help!

  • Like 2

Share this post


Link to post
Share on other sites

Correction. As this famous little loco has a next 18 interface I will use a decoder which fits without fiddling. The only fact that speaks against this plug and play method is the new MX 659 (also this is next 18 direct plug in) which is too long for the available space but may fit after modification. Especially as I saw that there is a sound project for this little loco existing which I can download for free.... Will download it and try it on a test loco with an MX645 before I decide.

Vecchio

Share this post


Link to post
Share on other sites

Hi Vecchio

1. Do you have a photo where it shows the resistor and diode and capacitor and Zimo decoder all connected together?  

2. Also I have a soldering station with variable temperature will this be okay to use to solder the home-made keep alive?

 

Thanks
Shelton

Share this post


Link to post
Share on other sites

 

1. Do you have a photo where it shows the resistor and diode and capacitor and Zimo decoder all connected together?  

2. Also I have a soldering station with variable temperature will this be okay to use to solder the home-made keep alive?

 

 

There are diagrams in the Zimo manuals, towards the back, which show how the components fit together.   Essentially, diode+resistor in series with one lead (noting orientation of diode - that is really important!), and then capacitors between decoder positive (blue) and decoder ground (the new wire).  The components Vecchio is using are on the larger size of what's needed - my units use surface mount resistor and diode as they are a fraction of the size shown. 

 

Soldering is a matter of small tip, holding the decoder down so it doesn't move, limited time with heat applied, and good hand control.

Share this post


Link to post
Share on other sites

Attention. Diode and resistor in parallel. Not in series as you want to limit the charging current but you want full current for the chip (and motor) in case of loss of track voltage.

Rest ok. For the diode you need a 1 ampere type or bigger depending on decoder and model as the complete current will run over it.

Cheers from the train to London. Delayed as usual and not enough seats....

Share this post


Link to post
Share on other sites

Attention. Diode and resistor in parallel. Not in series as you want to limit the charging current but you want full current for the chip (and motor) in case of loss of track voltage.

Rest ok. For the diode you need a 1 ampere type or bigger depending on decoder and model as the complete current will run over it.

Cheers from the train to London. Delayed as usual and not enough seats....

 

Depends how you parse my sentence above....    I can see there are two readings.    It is (Parallel diode and resistor) in series of the lead between decoder positive and capacitors.....

 

- Nigel

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.