Good for O gauge?

[steamy]

I'm working on a layout on Po and contemplating Hornby DCC before it's too late. I have a small weakness in that I am keen to have an a O gauge inglenook or loco shed. Would Hornby DCC be good for O gauge? The ampage sounds good, it would only be for one or max two locos, and mainly for the sound. (Drive the neighbours wild with a heljan class 26 brewing up teacup, teacup,teacup!

[96RAF]

The basic DCC kit will be OK (controller and power supply) but you need to check the motor stall current and pick a loco decoder that will carry that load. An other make Class 08 O Gauge loco has successfully been fitted with a TTS decoder which has a low current rating. Some O gauge decoders are quite large and have hefty current ratings. This leads to what socket fittings do your O guage locos have as unless they are compatible with standard NEM standard pin arrangments you may be stuck with hard wiring decoders in.

[steamy]

 Many thanks.  So, I should find out the current of the motor, and the current of the sound chip decoder.  Presumably from what I understand with a basic dcc controller the loc woudl run (albelit possibly a slower max speed than with one witha  higher current) and it is possible taht the sound woudl not work, if the current of the sound chip was higher.  Sorry if I sound like a dunderheid!

[96RAF]

Lets go back to basics.

To find the stall current of the motor it must be done under DC conditions. You must not do a stall check on a decoder equipped loco or you will likely damage the decoder. Brian Lamberts web site will tell you how to set up your multimeter to do a stall check - ensuring your meter can take high DC amps readings, some meters top out at 100-200mA on DC. For the check the deocder is unplugged and a DC blanking plate fitted.

 

Your DCC controller will come with a power pack of a specific rating - say Elite at 4-amps. If the total current draw on the layout is more than that then protective measures cut in and the controller will effectively shut down until the overload is removed. This may be too many locos on track or simply a short circuit for whatever reason. Some controllers (Select and eLink) come with a basic 1-amp supply thus limiting the number of trains you can run (total current load again) but these can be safely upgraded by using the 4-amp supply. Other make controllers usually have a similar power upgrade method.

 

Looking at decoders. Each decoder will tell in its spec sheet what its maximum motor and function loads are. Some will self protect if overloaded above these values and some do not - meaning they can be damaged if overloaded. You need to match the lco needs against what the decoder can provide. 

 

A motor will only draw as much current as it needs. For instance a lightly loaded loco going slow will draw minimal current by one loaded with many carriages or wagons running fast or on a gradient will draw more current up to the max (stall) when either the motor or the decoder will start to suffer.

 

A motor will not run any slower with a low amperage power unit nor any faster with a high amperage power unit. Its all a matter of balancing power requirement for motor load against the power available. A lightly loaded loco will run at max speed using a low power unit, but may not run if the decoder or motor is overloaded when using a higher power unit.

 

Going back to the original post it has been found that the Bachmann 0 Gauge Class 08 motor has such a low current requirement that a TTS decoder can safely be installed.

 

I hope that makes sense.