DCC Decoders have limits in terms of the level of power they can handle before succumbing to catastrophic failure. The threshold will vary between different types of decoder. So what are those power levels, how can a locomotive end up drawing such levels, and how can you mitigate the risk of decoder destruction on your layout. It's time to take a closer look.
We'll start by looking at the voltage and current that makes up the power consumed by a DCC decoder including the limits for some of the most popular decoder types.
We'll then look at the factors that can lead to excessive power draw in a locomotive and how this can ultimately lead to failure.
Finally, we'll look at how you can mitigate against over-driving your decoder and hopefully avoiding it's ultimate destruction.
00:00 - Introduction
01:00 - Decoder Power Limits
05:45 - Factors Affecting Current Draw
16:18 - Mitigating Potential Failures
19:38 - Summary
Some additional points raised in the comments.
The Sprog II (and later versions I suspect) has a number of current limiting mechanisms to help reduce the risk of a decoder pulling too much current and burning out. It also provides a current consumption readout equivalent to the Alpha Meter.
I didn't mention it but the speaker connections are another source of power consumption and potential damage if you short them to each other or other pins on the decoder, or use an incorrect speaker.
