[upnick]

Hi
After converting several of the farish 08's now i have come to the freightliner version i fitted an M1 decoder to it as the others & got a read back of 003 of course and proceeded to put it on the main track to try it, as soon at the wheels touched the track i got a wiff of smoke from the decoder, i have tested the decoder and it is working still, does anyone know any quirks as to why this loco might short out somewhere is it not dcc friendly at all ? as comparng it the my other odler 08's it is the same design.

 

[poliss]

Did you test it on DC first?

 

[upnick]

Hi Poliss,

Yes the loco was tested on dc before conversion and it was running fine.

 

[railstimulator]

When you say you tested the decoder, was it put in another loco or did you just try reading it's address etc on the test track?

The encoder/decoder in the master control is only programming or reading the loco decoders front end and the info stored in the memory. The backend is the rectifier and driver, if that has smoked then yes the front may still be OK but the output hi current end could be shot.

 

[Richard Johnson]

QUOTE (railstimulator @ 18 Jun 2008, 17:39) <{POST_SNAPBACK}>When you say you tested the decoder, was it put in another loco or did you just try reading it's address etc on the test track?

The encoder/decoder in the master control is only programming or reading the loco decoders front end and the info stored in the memory. The backend is the rectifier and driver, if that has smoked then yes the front may still be OK but the output hi current end could be shot.

*** Almost but not quite right. Yes its reading onboard data but the decoder acknoledgement is actually a reaction of the load on the motor drive. So.. if its reading when interrogated the motor drive circuit is able to acknowledge the query... so its possible its damaged ....but unlikely.

This motor drive aknowledgement is what creates the occasional physical movement of a loco during "reading" or writing. If the motor drive is open circuit a decoder will not be able to be read. It is in the order of a 60mA "ack" so if it can read back reliably then I'd bet on this decoders drive being OK.... if not, no matter, the TCS goof proof warranty will cover it.

***Upnick - did you use the DCCsupplies top hat kit for this, and did you also remember to ensure proper insulation of the connection / retaining clips etc... there is B all clearance with the 08 between a good install and a short, and it will really pay to double check for a short between bottom motor brush and chassis after the conversion.

To see a short once the leads are all installed betwixt motor and decoder etc you'll need to set the multimeter to ohms in its lowest range as you are looking for zero ohms as a short and somewhere above 30 ohms for a good install....

Richard
DCCconcepts

 

[upnick]

Thanks for the advice Richard, i havnt had the oppurtunity to test the 08 tonight though will follow up wth the multimeter, i used the Gerry spencer conversion which is a tight fit to say the least hope the insulation on the brushholder hasnt been damaged at all as the only way to resolve it is to drill it out and try again.