LCDR Posted May 25, 2019 Share Posted May 25, 2019 Can anyone tell me if I can use the Hornby TTS 08 decoder in a Gauge O Dapol 08, please? Will it give me full DCC control or will I need something else? Link to comment Share on other sites More sharing options...
Chrissaf Posted May 25, 2019 Share Posted May 25, 2019 I would have thought that an O gauge loco would have a bigger and more current hungry motor. The TTS decoder is based upon the basic R8249 for motor control which is rated at 0.5A continuous. So I would be asking myself the question.....what is the 'stall current' of the Dapol 08 Gauge O ?. Link to comment Share on other sites More sharing options...
96RAF Posted May 25, 2019 Share Posted May 25, 2019 Discussion on RM Web forum suggests using a separate motor decoder for drive and TTS for sound. Link to comment Share on other sites More sharing options...
jane1707819582 Posted May 25, 2019 Share Posted May 25, 2019 i think it's a job for a loksound 5 if sound required . and suggest a 1.5 amp decoder without Link to comment Share on other sites More sharing options...
LCDR Posted May 25, 2019 Author Share Posted May 25, 2019 Thanks, - food for thought there! Link to comment Share on other sites More sharing options...
Howbi Posted May 25, 2019 Share Posted May 25, 2019 LC.............I have just bought a Dapol 'O' gauge Terrier and have got already an Econami sound decoder which is rated at 2 Amp stall current........it is cheaper than a Loksound..........HB Link to comment Share on other sites More sharing options...
Phil_Spiegel. Posted May 25, 2019 Share Posted May 25, 2019 The TTS Decoders are rated for 0.5A continuous and 1Amp max - with no functions on (0.8Amax with functions)They are also rated properly for the 'full dcc voltage' limit of 27V ... although most often 15-16V on track which gives about 12V across a motor by the time it has passed through the diode bridge and then driver stage.(Some makes are only rated for '16V' - 'allowing' the use of lower voltage rating capacitors which are usually smaller)My brother's experience with the Dapol 0 gauge locos - including dieselshunter is that the current is surprisingly low ... albeit that is running on level track, and even with a long 0 scale layout - you don't get much in the way of coaches or wagons behind one 8-)It rather shows the benefits of having a multimeter.... if the motor shows about 20 ohms or more there should be no problem .... if marginal, do what I am trying in preparation for 'future tts use' in Heljan 00 locos ... motor resistance of a Heljan western tested today was just under 8 ohms .... a 10 ohm high wattage resistor in series with the motor will prevent the current increasing beyond a safe value - and the loco still runs okay (not yet tested on a gradient with load ... where it MAY show 'underpowered' but will not damage a decoder !!!! V=IR Possible near worst case scenario: 8ohm motor +10 ohm resistor =18 ohms 1Amp = 10W resistor18V ( for easy figures) = 1 Amp x 18 ohms - but 14-16V track voltage gives a proportionally lower maximum current12V at the motor (about 15-16V on track) would have a maximum of 2/3 Amp .with 18ohms 1/2A with 24 ohms.Note: when measuring motor coil resistance - as you turn the motor, you will find 'dips' in the reading as it switches from pole to pole - because 2 coils are momentarilly in parallel ... THIS IS the worst case stall position !!! - paralleled coils and no back emf from movement to reduce the current demand. - but, unless the mechanism is jammed (eg by bent valve gear), it is only momentary, and once the motor is turning, there is back emf reducing the current. Link to comment Share on other sites More sharing options...
LCDR Posted May 26, 2019 Author Share Posted May 26, 2019 Thanks but that all sounds a bit too technical for me. I was hoping for something I could plug straight in. Link to comment Share on other sites More sharing options...
Phil_Spiegel. Posted May 26, 2019 Share Posted May 26, 2019 For those unwilling or unable to make the simple measurement themselves - my brother has reported back to me that the motor resistance is 82-83 ohms .... higher than I expected - such that I asked him to recheck before publishing the figure here 8-) That implies that the 08 should be able to run bery happily on the Hornby TTS decoder ! .... you just need an appropriate adapter to 21pin to fit it - included with some decoders.For the Dapol DMU/ bubble cars in 00, the 21pin socket is very close to a partition wall, and therefore I believe the 21-pin BREAKOUT pcb available will not fit - because it has 2 rows of solder tab connections available on each side ot the socket .... whereas normal 21pin decoders haver the socket mounted at one end.IF the pannier tank has a similar motor resistance, then a TTS steam sound decoder should be able to work okay in that as far as current consumption is concerned - I don't know what model may be best of those currently available - or how motor gearing will affect the chuff rate 8-) .... that is for someone with 0 gauge to try ... we only have H0 00 and G Link to comment Share on other sites More sharing options...
Phil_Spiegel. Posted June 2, 2019 Share Posted June 2, 2019 my brother has now confirmed that his dapol 0 gauge shunter worked well with the tts 08 decoder .... but reportedla bit quiet with the original speaker ... and as there is room, he will fit a larger type and ensure its enclosure is properly sealed ( the original being only for test) Link to comment Share on other sites More sharing options...
LCDR Posted June 3, 2019 Author Share Posted June 3, 2019 I got a speaker and chip from Brian from the other Forum, and fitted it this weekend. It seems to be working fine using myt Prodigy Advance. I was terrified soldering the speaker into the mechanism, being so close to the plastic bodywork. My hands are not as steady as they used to be and my eyesight not as good either. For my peace of mind I think I will get the rest done by professionals. Link to comment Share on other sites More sharing options...
Phil_Spiegel. Posted June 3, 2019 Share Posted June 3, 2019 Perhaps a longer- term more useful approach is to use leads with plugs and sockets -I use 'JST MicroMini 1.27mm' PREMADE leads- male and female - of the same style as used by Hornby to connect steam locos and tenders . These are readily available in packs of 10 or 20 via Ebay with 2-pin or 3 pin connections ( but 4 pin male and female seems to be unavailable at present - only Male, and female sockets )Then your soldering, or as much as possible of it - can be made safely away from the Loco body - and rested externally perhaps.Alternatively - do you have some small 'sheets /plates' of metal that you could locate inside the model - possibly taped to the sides - so that the risk of the iron tip or shaft touching the plastic of the bodyshell is minimised. Link to comment Share on other sites More sharing options...
oldpottsline. Posted June 3, 2019 Share Posted June 3, 2019 The answer to the OPs question is a simple NO. Link to comment Share on other sites More sharing options...
The Grid Posted July 11, 2019 Share Posted July 11, 2019 The answer to the OPs question is a simple NO.How strange, I have a Dapol O-scale 08 shunter working perfectly well with a Hornby TTS decoder. The only modification I made was to use a Mega Bass 1 inch square speaker (with enclosure) in place of the Hornby original - this readily fits behind the radiator at the front of the Dapol locomotive. Speaker can be purchased on eBay, see:-eBay item number:264198095071 Link to comment Share on other sites More sharing options...
96RAF Posted July 11, 2019 Share Posted July 11, 2019 The answer to the OPs question is a simple NO.OP asked three questions. Link to comment Share on other sites More sharing options...
Fishmanoz Posted July 12, 2019 Share Posted July 12, 2019 A bit hard to answer no when the OP has already fitted it, based on comprehensive yes answers given and it is working? Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.