OK, so I gather no takers…
basic laws, take the voltage drop across a device, multiply it by the DC amps, you have watts. This power has to be dissipated somewhere and unless your device glows like a light bulb, creates radio waves, magentism, or nuclear radiation, it’s all in heat.
It’s that simple, just like the sum of the voltage drops in a complete circuit must equal the voltage source.
That the law of conservation of energy. The universe and this world would fall apart without it.
So just be sure to check how much power you are dissipating in your regulators, a 1 amp regulator needs heat sinking way before it gets to 1 amp, and the spec sheet on the regulator will even tell you about how much current it will handle at what temperature.
With no heat sink, it’s surprising how little heat (current) the TO-220 regulator package can handle. Also, remember there is very little cooling air flowing inside most locos.
Regards, Greg