DCC and TMCC

The DCC signal is an AC square wave at around 29K Hz but it isn’t a perfect square wave. The tops and bottoms of some of the squares are lengthened to make the zeros and ones which make up packets of instructions. This is why DCC works so well. It’s because the power is also the signal or instructions to the locomotive. You can’t have one without getting the other. With your idea how would the ones and zeros get to the locomotive? 

I think you got a good idea but how about a circuit that filters the DCC signal and changes it to a sine wave. Then the TMCC locomotive would get the power it needs to operate while getting its instructions through the antenna?

But I guess that won’t work because I think TMCC needs the 60Hz signal to broadcast the instructions. 

One time I ran a PS2 locomotive in a DCC block and I could hear the DCC signal in the speaker of the locomotive. It seemed like it was going to work but I didn’t want to chance damaging the electronics. 

The Dcc power source must convert the 60 Hz a.c. to the 29 kHz somehow before it goes out to the track. 

I was wondering if the same circuitry could be installed in the engine rather than the power source. 

Trainman2 posted:

The Dcc power source must convert the 60 Hz a.c. to the 29 kHz somehow before it goes out to the track. 

I was wondering if the same circuitry could be installed in the engine rather than the power source. 

That is certainly possible or doable but again how would you get the instructions to the DCC locomotive?

I would guess that would depend on how the handheld device gets the instructions to the locomotive.

Does it go directly to the decoder, or does it have to get added in at the power source?

I would guess that would depend on how the handheld device gets the instructions to the locomotive.

Does it go directly to the decoder, or does it have to get added in at the power source?

I ran a Legacy loco and an MTH loco off DCC power the MTH loco was in DCC mode and the legacy loco was running Legacy. Both ran and worked but the legacy loco had feed back thru the sound system.

S cab and dead rail both talk of using on board radio control receivers with dcc technology, and battery power.

I  would think track power and a rectifier could substitute for the battery. 

I use dcc dc ac dcs and tmcc on the same layout by using main one and main two toggle switches plus on off siding switches. Works well in s gauge and in 0 except fastrack switches 

Matt Makens posted:

I ran a Legacy loco and an MTH loco off DCC power the MTH loco was in DCC mode and the legacy loco was running Legacy. Both ran and worked but the legacy loco had feed back thru the sound system.

Could you please post a sketch of the wiring, what DCC command hardware you used, and a video?  A couple months ago I asked about doing just this and was told it wouldn't work.

I realized DCC's underlying or base current is AC, but just so I have this right, analogy or sinusoidal 60Hz AC gets converted to squared off or flat 29kiloHertz - correct?   Thanks.  

Sgaugian posted:

I realized DCC's underlying or base current is AC, but just so I have this right, analogy or sinusoidal 60Hz AC gets converted to squared off or flat 29kiloHertz - correct?   Thanks.  

Its difficult to equate DCC to a base frequency because "0" bits have a square wave period thats at least twice as long as "1" bits. 

Going off of memory, which is dangerous, but I believe 1 bits have a frequency of 8-9khz, and zero bits have a frequency that is half of that, but could be much lower due to a technique called zero-stretching. 

So while wall power is a continual 60 hz frequency, DCC varies the frequency of the alternating current so that the information can be passed and detected as 0 and 1 bits.