Found some info on watts/amps

Classic Toy Trains Forum
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In another thread on milk cars we were talking about how many amps a milk car draws. This got me to look up some more info on watts/amps…

18 Watts = 1 amp

Single Motor loco uses 45 watts

Double Motor loco uses 90 watts

Operating accessories (like 164, 364, 397, etc) use 40 watts

Trackside signals (151, 252, etc) use 15 watts

6 volt lamp uses 1.5 watts

14 volt lamp uses 3 watts

Also found out how to calculate the amp capacity of a transformer. Watts / Volts = Amps. A ZW tranformer would be calculated as follows (275W / 20V = 13.75A) But the ZW only have a capacity of 180 watts. The rest was used in reducing 120V to 20V. So don’t exceed 10 amps.

Found this info at thortrains.com

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You’ll probably hear from others who are far more competent than I, but don’t assume that every 14 volt bulb, for example, produces 3 watts of power. As you noted, power (or watts) is based on the product of volts and amps. So, some 14 volt minature bulbs may draw 0.1 amps while other 14 volt bulbs draw 0.3 amps, resulting in 1.4 Watts and 4.2 Watts respectively. So, your list is a good guide, but to understand what power is being needed, you need to know at least two of the three factors (volts, amperage, or watts). The Thortrains.com site is a great reference. Thanks for citing it…RJ