Tag: Soldering

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Hornby Class 37 TTS Sound Mini-Series – Part 2: Adding a Stay Alive Capacitor to a Hornby TTS Decoder

Welcome to Part 2 of our in-depth mini-series looking at improvements and upgrades to Hornby TTS sound decoder-fitted locomotives. In Part 1, we looked at speaker upgrades, and in this second part we’re looking at making a stay alive capacitor unit and fitting it to the decoder.

Whilst focused on the Hornby TTS decoder, the principles and steps outlined in these videos are applicable for most other stay alive scenarios, including other types of decoder, coach lighting circuits, end of train (EOT) lamps and so on. It’s ideal viewing for anyone interested in this areas of railway modelling.

Making the Stay Alive/Keep Alive Capacitor Unit

As well as showing you how to make the stay alive unit itself and assemble all of the components, in this video there’s a brief explanation of the background to stay alive devices generally and the role that each of the components plays in the overall circuit.

+ Video Contents +

00:00 – Video introduction
01:08 – Intro to making a stay alive unit
02:18 – Overview of the components required
04:11 – Using resistors to manage in-rush
05:00 – The components in detail
06:26 – Circuit diagrams
08:40 – A quick word of capacitor sizes
10:58 – Putting it all together: soldering
15:40 – Adding hookup wires & heat shrink
17:22 – The finished article

Fitting the Stay Alive Unit to the TTS Decoder

In this final video, we look at adding the stay alive/keep alive unit that we made to Hornby’s TTS sound decoder. We look at where to solder the two wires and also how to adjust CVs on the decoder to ensure that the stay alive unit functions correctly.

While the specific steps relate to Hornby’s TTS decoder, if you wanted to add a stay alive unit to their entry level R8249 decoder, the steps would be fairly similar (although the negative leg would have to be soldered directly to the negative side of the rectifier). If you’re using a different brand of decoder, the principles will be very similar, but the solder points will be different.

+ Video Contents +

00:00 – Introduction
00:20 – A quick recap
01:20 – Examining the decoder
06:08 – Soldering it all together
14:52 – Testing the solder work
16:10 – Fitting it all into the chassis
18:05 – A word about CV settings
19:08 – Testing the stay alive unit
20:53 – Conclusions

Please note: the steps involved in fitting the unit do require a steady hand and competence with a soldering iron. Working with DCC decoders and tiny surface-mount components leaves little margin for error and it is very easy to permanently damage sensitive electronics if you are not extremely careful.

Circuit Diagrams

We’ve produced a couple of circuit diagrams to accompany this tutorial series. You can download copies for free using the links below:

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Hornby TTS Decoder Stay Alive Installation Instructions (COB Side) 3.27 MB 1867 downloads

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Hornby TTS Decoder Stay Alive Installation Instructions (Rectifier Side) 2.89 MB 1159 downloads

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Project Components

You can buy items used in these tutorials using the affiliate links below. Using these links helps to support this website and our associated YouTube channel and is very much appreciated.

Hornby TTS decoders (Amazon): https://amzn.to/2PbRM9x
Hornby TTS sound decoders (eBay): https://ebay.to/2S1P4Ca
Capacitors (15,000 uF 25v): https://ebay.to/2AljFnF
Resistors (100 ohm 1/4w): https://amzn.to/2yzLtDx
Decoder wire (red & black): https://ebay.to/2NR9fj1
Decoder wire (Multipack): https://ebay.to/2PGEYoK
Diodes (1N4001 50v 1A): https://ebay.to/2CXBifB
Diodes (1N4001 50v 1A): https://amzn.to/2ODFqYo
Heat Shrink (multipack): https://amzn.to/2PdO0N5
Heat Shrink (various sizes): https://ebay.to/2EvWI54
Kapton tape (10mm x 30m): https://amzn.to/2OBEpjB
Kapton tape (various sizes): https://ebay.to/2R2H2aU
Liquid Flux Topnik No Clean (Amazon): https://amzn.to/2Al6HpP
Liquid Flux Topnik No Clean (eBay): https://ebay.to/2CXy7EO
0.3mm Lead/Tin solder: https://amzn.to/2NT7pOy
0.3mm Lead/Tin solder: https://ebay.to/2S6Jpe0
Hakko Soldering Station: https://amzn.to/2CVLzca
Blue silicone electronics mat: https://amzn.to/2Pbv7ug
A2 green cutting mat: https://amzn.to/2P8aKy3
A1 green cutting matt: https://amzn.to/2P8aKy3

Disclaimer

This project does require a steady hand and competence with a soldering iron. Working with DCC decoders and tiny surface-mount components leaves little margin for error and it is very easy to permanently damage sensitive electronics if you are not very careful. If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.

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Hornby Class 37 TTS Sound Mini-Series – Part 1: Mega Bass Speaker Upgrade

The is the first in a two-part series on upgrades and improvements that can be made to a Hornby Class 37 locomotive with TTS sound.

In the second video, we’ll look at adding stay-alive capabilities to help keep the running smooth and steady, but for now, we’re upgrading the stock speaker to something a little better…

The steps outlined in this video are applicable to all TTS sound decoders (and many others). The only differences being that in some locomotives – not least most steam locos – the space inside can be rather limited and you may not be able to fit such a large speaker into the body.

Remember that in all cases where a Hornby TTS decoder is used, you must also use a 8 Ohm speaker (or two 4 Ohm speakers in series, adding up to 8 Ohms). This is different to LokSound V4 decoders, which can use a 4 Ohm or 8 Ohm speaker.

Speaker impedance and decoder specifications for all common sound decoders are explained in more detail in our free guide, which you can download here:

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Railway Modelling - Matching speaker impedance to DCC sound decoders 258.33 KB 613 downloads

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Getting components for this project

You can buy some of the components and consumables used in this video, and give a wee bit of support to the channel, using the affiliate links below:

Megabass speakers: https://ebay.to/2N4VMnf

‘No Clean’ Solder Flux: https://amzn.to/2E9oOmK

Selection box of heatshrink: https://amzn.to/2zTbhv5

Black tack: https://amzn.to/2OCYhCg

 

Please note: If you choose to follow any of the steps or suggestions outlined in the video, you do so at your own risk and any damage or injury to yourself, your models, your equipment or others is your own responsibility.