DCC Bachmann equipment on 12V layouts

[TrainArts]

I did a search for the answer but didn't see a clear answer, forgive me if this has already been addressed.

Are all Bachmann DCC-equipped locomotives able to run on 12V layouts? Is this called a "dual-mode" decoder?

If yes, does anyone know if there are specific exceptions?

I specifically need to run a On30 rail truck on a 12V layout.

Thanks for any help.

Jim

[jonathan]

Jim,

Bachmann advertises that their 'DCC on board' locomotives will run on a DC layout, right out of the box.

This has been true for my equipment.  Although I model HO, not On30.  I suspect it should be true for On30 as well.

Regards,

Jonathan

[rich1998]

the only downside you might say, is you have to turn the controller up higher than you normally would on a dc only loco. usually the loco will not start moving until the voltage is around 7 to 9 volts. If the loco has sound, the sound may start around 5 volts before the loco moves. i have monitored this with a multimeter. your mileage may vary
lex

[TrainArts]

Thanks everyone for the fast answers, I appreciate it.

Lex, what you say is interesting, is it purely a voltage issue? I wonder, did you test with the basic cheap Bachmann throttles vs. a Spectrum or a Tech4?

I guess I'm ignorant in this area, is there a "signal quality" issue with DC like with AC?

Jim

the only downside you might say, is you have to turn the controller up higher than you normally would on a dc only loco. usually the loco will not start moving until the voltage is around 7 to 9 volts. If the loco has sound, the sound may start around 5 volts before the loco moves. i have monitored this with a multimeter. your mileage may vary
lex

[rich1998]

a lot of confusion occurs because many people are not aware of how decoders work.
not trying to be smart, but do not assume.
logic circuits usually operate at about 5 volts dc. the micro processor circuits need about that much voltage to begin operating.
please be aware that the motor does not operate at dc voltage in the loco. the decoder circuits send pulse power to the motor.
standard for any decoder equipped loco. the decoder also makes pure dc to operate the lights.

the motor needs a little more voltage to overcome the cogging action of the motor armature.
i gave away all my old dc power packs.
i now us a 12 volt rechargeable battery for pure dc with a variable resistor to control the voltage.
i have some multimeters to measure dc voltage and current.

put it this way, the loco might act a little differently using dc to control the dcc loco. does not mean bad, just different.

going from dc to dcc is a big step as digital control allows so much more to be done.

i remember tv's that you had to go up to to change the volume, channel, bang on the side to get better reception, adjust the rabbit ears for better reception. you laugh, but it was like that back in the 1950's. no such thing as a remote control.

lex

go to the below link and look around. the part on "pwm for the motor" is what you motor "always sees" whether you use dcc or dc to operate the dcc equipped loco.

http://www.awrr.com/dccintro1.html

[Jim Banner]

... is it purely a voltage issue?

No.  But is is a characteristic of decoders.  To put it simply, the decoder requires some minimum voltage before it can start to work.

The only problems this might cause are
(1) if you are trying to run a decoder equipped locomotive or other mobile unit along with a similar unit without a decoder, the one without the decoder will be off and running before the decoder equipped one starts.
(2) the maximum speed of the decoder equipped unit with be less than the maximum speed of the similar unit without a decoder.

Run by itself, a decoder equipped unit will run just fine on dc unless you are trying to run it like a slot car.

If you must match it to a similar unit with no decoder, then bypassing the decoder is the only way to go.  This can be as simple as unplugging the decoder and plugging in a "dummy plug" in its place or as hard as clipping two wires and soldering them to the decoder in a different place.  The latter may require some skill in soldering fine wire onto crowded printed circuit boards i.e. it is not a good project on which to learn soldering skills.

Jim