Hornby TTS chips

[mikeg]

Does anyone know if Hornby TTS chips have an overload cutout I have just put one in an old Hornby A4 the sound is working but it will not run, it starts to move then stops no sound and will not start up again for a period of approximately 45 seconds when sound will work but it will not move.

If I disengage the gears the armature will run upto speed step 15 and then stops but the sound then stops for 5-10 seconds after which the motor will start but stops quickly, which makes me think there must be a cut out. On DC it draws 0.4 amp so is within the 0.5 amp running amps on the package it comes in, the DC amps measurement is with a rammetter unit.

Any thoughts as to what is wrong?

 

Mikeg

[RAF96]

The motor control side of things is self protecting but the function outputs are not.

 

Edit - is this the only loco doing this or is it maybe a controller shutdown.

Rob

Edited November 12, 2018 by RAFHAAA96

[mikeg]

The motor control side of things is self protecting but the function outputs are not.

Edit - is this the only loco doing this or is it maybe a controller shutdown.

Rob

Rob, as the owner only has one other loco and that is OK I think it is only this one that is not working as it is the same on my gaugemaster and his NCE unit I think it may be the magnet that is the problem although it runs well on DC and the magnet attracts a screwdriver OK which makes me think that something else is wrong.

Thanks for the reply

Mike

[Phil S]

I am slightly confused by the changing reference between 'I' and 'the owner' along with the extra info of one other loco [no info] ... now realising this is a loco you have converted for someone ?

 

The behaviour IS symptomatic of a short/overload and the decoder protecting itself [ motor and function part ] ....

what was done with the unused function leads yellow,white,green and blue from the decoder??....

. were they individually insulated to ensure no shorting ....

. even though these may have no 'protection' individually, they still take current through the bridge rectifier on the decoder's input side ... thereby causing it to protectively shut down.

 

Is this an old tender drive A4  or a more recent loco drive model?

Personally I do not consider the old tender drive models worth converting [again] .... having already converted mine twice for Zero-1 when it started [ and then swapped direction a few weeks layer ] and then qgain for dcc [silent]!

Edited November 13, 2018 by Phil S

[mikeg]

Phil, yes I have converted it for a friend, I have insulated all the other wires so no problem with them, I think that the problem is with the motor magnet or that the gear train is gummed up with years old lubricant dried up through not being used (approximately 30) although it ran well on DC as noted.

I am going to strip the motor and clean the gears to see if that improves the problem.

Thanks for the reply mike

[RAF96]

My problem was a (ringfield) loco would run nicely on a rolling road but could not drag its own weight around the track.

 

I had one ringfield motor that I put a neo magnet in and that runs sweet as a nut, but in another the magnet was just too strong and the motor would only run flat out and was very notchy when turned by hand.

 

In the end I got a new motor housing for it complete with magnet and it has been OK since.

 

Yet another was fitted with a CD tray motor and that runs nicely too.

 

I have found that some ringfields can have a dodgy connection method to the motor housing return by way of a spade connector onto a lug. I have drilled and tapped to provide a better connection on a couple of mine. I have also fitted more pickups to the front bogie using slightly later model parts where possible.

 

TTS decoders - setting CV150 to value 1 improved my old Lima ringfield motored loco, so keep that in mind, however from all the above and previous posts it sounds like a weak magnet compounded by accumulated gunge, which can also affect the wheel/axle current carrying ability.

 

Rob