@gunrunnerjohn posted:Not sure where you're getting your numbers from, but a 24 ohm resistor with 9 volts across it would be drawing 375 ma, that's true. However, that is a power dissipation of 3.375 watts, that would take that resistor to the woodshed in a hurry!
Yes your are correct, I forgot to say that 56 ma is the .5 watt rating of that resistor at 9V, at the low charge volts of about 2 was drawing about 150ma which is about .3 watts, and and when it jumped to 9 at around 70 ma or so, actually the trip point was between 50 an 70 ma on the Simpson 260, that would actually be a bit over 1/2 watt, but it did come down quickly towards 50ma. The actual charge voltage when it jumped up from 2 was between 8 and 9. I wondered if the charge circuit initially messed up and put the full 9 volts on the, basically shorted/discharged BCR, and did not downshift to the 2 volt level. As you noted, if it did fail to switch to the low 2 volt charge voltage, and put 9 on it, your 3.375 watts would smoke the resistor just like it did. I did experiment with 3 different MTH locos and they all did the low 2 volt initial charge voltage until the current was in the 50-70 range, and then shifted up to 8-9V charge volts.
