Zimo MX621 stay alive

[PaulT]

The Zimo manual on line says MX621 can have external capacitor (with diode and Resistor) but the pin layout is only given for MX620 which is different.

 

Where do I connect for the 621?

[Edwin_m]

According to this summary, it's not available on the miniature decoders. And if my German is up to the job then it would appear to be only the MX631 or above.

 

The MX621 is a cut-down version of the MX620 designed to reduce the size by eliminating less-used features, and it looks like this is one that has gone. There ix a MX622 planned which is roughly the equivalent of the old MX620 but this is one feature that it doesn't seem to have.

[Nigelcliffe]

According to this summary, it's not available on the miniature decoders. And if my German is up to the job then it would appear to be only the MX631 or above.

 

Nah, I think you've mis-read the occaisionally complex Zimo documentation. The MX631 (etc) have the auxillary components included on the circuit board, so only needs a capacitor. The smaller decoders have the old arrangement of +V and 0V pads, and require diodes, resistors, etc. as well as the capacitors. Both are described in the current Zimo manual.

 

Back at the solderpads for the 621.. There should be something labelled "ground" or "0V" which is one side of the circuit, and if I remember my Zimo manuals correctly, the Blue output can double for the +V power tab. (Sorry, away travelling, so all of my data files are not with me. ).

 

- Nigel

[Edwin_m]

That makes sense Nigel - sometimes Zimo don't do themselves any favours by way of promoting the things their decoders can actually do!

 

I think the problem may be that the latest English manual pre-dates the MX621. Looking at the later German version the pictures on page 5 show a pad marked "MASSE" which is the decoder ground and "blau" is the positive.

[PaulT]

 

Back at the solderpads for the 621.. There should be something labelled "ground" or "0V" which is one side of the circuit, and if I remember my Zimo manuals correctly, the Blue output can double for the +V power tab. (Sorry, away travelling, so all of my data files are not with me. ).

 

- Nigel

 

Yes, those two are identified and in line with other makers I wondered if the stay alive connections should use those.

However I was made hesitant by seeing the pictures for MX631 on page4 which show "Capacitor negative, this is NOT ground".

I suppose that is because the 631 has a choke between Cap neg and true ground.

[PaulT]

That makes sense Nigel - sometimes Zimo don't do themselves any favours by way of promoting the things their decoders can actually do!

 

I think the problem may be that the latest English manual pre-dates the MX621. Looking at the later German version the pictures on page 5 show a pad marked "MASSE" which is the decoder ground and "blau" is the positive.

 

Ta for that. Nigel and Edwin.

I now have courage to connect R,C & diode to Blue and Ground!

[Nigelcliffe]

That makes sense Nigel - sometimes Zimo don't do themselves any favours by way of promoting the things their decoders can actually do!

 

I think the problem may be that the latest English manual pre-dates the MX621. Looking at the later German version the pictures on page 5 show a pad marked "MASSE" which is the decoder ground and "blau" is the positive.

 

Edwin, Yes, that manual covers it. Page 54 covers the installation of capacitors on the smaller (and older) decoders including the MX621.

Google translate should do a tollerable job on the section required if not able to read German.

 

 

PaulT. Yes, you've got it right, the "Capacitor Negative" for a MX631 does have additional components between it and the true decoder ground.

 

 

- Nigel