What Diode Hornby Decoder R8249 ?.

[itsthegman]

Does anyone know what type or model diode is used on the Hornby R8249 decoder.

 

I have some failures and need to replace them.

 

Thanks,

 

G.

[Crosland]

If it's one of the 4 that rectify the DCC signal then they should really be ultra fast or fast recovery type, something like a UF4001 but in smd packaging. 1 Amp should be fine. Lowest reverse voltage rating is usually 50V for this type of diode, which will be fine.

 

What are you doing to destroy the diodes 

[RAF96]

MBR0530 (R8249) or possibly MBR230LSFT1G (TTS) will be OK.

 

Edit to add links

 

http://www.alldatasheet.com/datasheet-pdf/pdf/172656/UTC/MBR0530.html

 

http://html.alldatasheet.com/html-pdf/205105/ONSEMI/MBR230LSFT1G/1129/5/MBR230LSFT1G.html

Rob

Edited May 18, 2018 by RAFHAAA96

[itsthegman]

Ok,quick update on this - success.

 

After advice given i searched for and purchased these.

 

https://www.ebay.co.uk/itm/20-X-MBR0530-FAI-Diode-Schottky-rectifying-30V-0-5A-SOD123-MBR0530/112699767688?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

 

I have just replaced two on my Hornby decoder with my iron a 1mm tip and solder paste.

 

I fitted it to the donkey my test chassis checked out on the programming track, when it read back address 105 i was a happy man.

 

Loco runs under dcc power doesn't seem to have suffered any ill effects so far. Once i have carried out more testing with some extensive train playing i will be very happy.

 

Crossland, you did ask how i did it well i had my own stay alive pack made up of 6 x 100uf surface mount caps but and yes i know it was wrong no resistor or diode setup it just went pop one cap is rather black so must have shorted.

 

I've made it this far using normal large caps and no real issues apart from my rushing to the track without proper insulatation.

 

So here we are i have done one i will try another that i have removed suspected faulty diode's from and we shall see but happy for the moment.

 

I'm not going to put out a request just yet for duff Hornby decoders but one day maybe.

 

Will update when i have done the next one.

 

Thanks for the advice guys.

 

TBC.

 

G.

[Finsbury]

I have never seen (albeit limited experience) such fantastic slow speed capabilities from a decoder, quite literally 'make a cup of tea,' and come back to witness a vaguely measurable movement in the meantime. it really is a shame that the r8249 cannot do much more.

Good luck with your trials and keep us informed.

 

kr,

Bernie

[RAF96]

I have never seen (albeit limited experience) such fantastic slow speed capabilities from a decoder, quite literally 'make a cup of tea,' and come back to witness a vaguely measurable movement in the meantime. it really is a shame that the r8249 cannot do much more.

Good luck with your trials and keep us informed.

kr,

Bernie

It’s time Hornby brought out a new more capable basic decoder. A shame they never leave the door to R&D open far enough to sneak a look at what future projects are on the bench. We hear plenty about forthcoming models in The Engine Shed, but never about new basic kit.

 

Anyone like to start a list....?

Rob