How much amperes does a sound locomotive need

[khier]

Dear All,

The majority of boosters have 3A rating. Most of H0 DCC decoders are 0.7A. I always translated this to 4 locomotives/booster. This simple relation was ok for me because I could not imagine running 4 locomotives at full load in one segment. Or I could simply divide it into two if the load is too much for a single booster. But when it comes to sound locomotives I am afraid this rule of the thumb will fail. Why? Because sound decoders consume power even if they do not move. I could use of course the nominal rating of the decoders to adujst my calculations. But I am curious if someone made actual measurements of the current drawn under real operational conditions to have a better estimation of the load and better design (or better say pre-design).

Regards

Walid

PS. Hopefully this discussion will not turn into a religion war like my previous thread.

[Graffen]

You could easily measure the amperage draw with a multimeter. But as I remember, the idle current on a sound decoder is very low.

[rrinker]

 I've had as many at 10 locos, 5 sound and 5 non sound, MOVING at the same time on a 3 amp system. I think most people far overestimate the power requirements of their locos. Or they are all running ancient Athearns with the old black motors, or brass with big open frame Pittman type motors.

                                           --Randy

 

[khier]

Randy, Thanks for the input. My busiest segment will not exceed 5+5.

Regards

Walid

[richg1998]

Some years ago I built two DCC amp meters using the below circuit. The circuit uses the cheap Harbor Freight multimeter on the 20ma DC scale. It trips about 4.97 amps on the club NCE five amp Power pro. I clipped a rheostat across the rails and lowered the resistance until the booster tripped.

http://www.circuitous.ca/DCCammeter10.html

For the club, I used the voltmeter option with a large LCD meter so everyone could see the display in the club.

Edit.

Been maybe ten years but I recall we were running about ten locos and drawing about three amps. Sound and non sound locos. Time's fun when you are having flies.

Rich