2 Decoders in a Ringfield A3?

[FlyingYorkshireman]

Hi Everyone, this may sound a bit cock-eyed but I have an old A3 tender drive which I fitted a TTS Sound chip to. unfortunately, no matter how much cleaning I have done on the motor etc, the chip cuts off power after a few seconds. Someone has previously said on here that TTS sound chips are not powerful enough to drive the ringfield. Could I fit another, say a Ruby (Gaugemaster) chip to drive the motor & leave in the TTS for the sound, which I am happy with?

[RAF96]

You could on a diesel, but not on a steamer as the TTS decoder relies upon BEMF from the motor to keep the sound on track. Nor can you slave the motor outputs in parallel as any feedback from one to the other will damage the decoder seeing the opposing DC voltage.

[Tim123]

I thought the reason for TTS decoders being relatively cheap is that they don't read feedback from the motor? The sound is based on what the decoder thinks the motor should be doing . I'm sure I've put a TTS sound tender from a J36 on the track without the loco being plugged in and I wondered which loco was chuffing without running. 

[Pete the Elaner]

19 hours ago, RAF96 said:

You could on a diesel, but not on a steamer as the TTS decoder relies upon BEMF from the motor to keep the sound on track. Nor can you slave the motor outputs in parallel as any feedback from one to the other will damage the decoder seeing the opposing DC voltage.

 

No it doesn't. One of the drawbacks of TTS is that the chuffs cannot be synced with the wheels.

 

18 hours ago, Tim123 said:

I thought the reason for TTS decoders being relatively cheap is that they don't read feedback from the motor? The sound is based on what the decoder thinks the motor should be doing . I'm sure I've put a TTS sound tender from a J36 on the track without the loco being plugged in and I wondered which loco was chuffing without running. 

 

That is one of the reasons TTS are cheaper.

They have other drawbacks compared to Loksound & Zimo decoders too:

 

They do not support advanced consisting.

They have a lower maximum current output.

They only support 2 concurrent sounds (engine + 1, so if you have a compressor running then sound the horn, it will fade out the compressor to sound the horn then fade it back in).

Motor control is less tuneable & poorer to start with.

It only supports 8ohm speakers. A 4ohm one will overload it.

They are only available with an 8 pin plug.

Volume is less adjustable (my class 60 would not respond to any volume adjustment.

They cannot be re-blown with a different sound project for use in a different loco (or upgraded at a future date).

 

If any of these are important, then a TTS is not for you. If none are important, then TTS is a bargain.

 

[RAF96]

@PtE

I will rephrase that.

TTS chuffs are recorded in as many as 18 chunks. The chunk in use depends upon the throttle setting vs road speed achieved. BEMF is used to determine if the loco needs to chuff or coast, i.e. is it accelerating or decelerating. As you say TTS actual chuff to wheel synch cannot be adjusted as it is set in production as best as possible given it is in chunks and the wheels are smoothly changing rate.