Further testing accessory side on the New CW80 Fanless transformer:
Works basically identical to the track power side from a safety or overload perspective.
Same set operation at previous CW80. Hold the 3 buttons DIR, HORN, BELL, light blinks green, raise handle to desired accessory voltage, release buttons and lower handle back to 0.
Max voltage with only a lightbulb was 19V.
Set to 12V for testing
6 Ohm load no issue.
3 Ohm load red led blinking and then shutdown in 5 seconds.
Once accessory output is tripped you must power cycle the transformer to reset. -Different than the track power as lowering the throttle to zero will reset a fault on that channel.
Again, my impression is, the new CW80 is an improved design over previous CW models. The new control board design that is fanless is a big bonus and it's not just about removing the fan, the overall circuit is just a lot better. That said, this is still a microprocessor controlled device. The firmware and design decisions put into that ultimately control how this works.
The choice of how to handle intermittent overload and or shorts, and when they trip off VS allowing the load could probably be a multi page debate.
Because the bell and whistle as well as the direction button tell the microprocessor the user input, and then the processor controls the output- there is a delay between user and output. I don't have good numbers on what that is, but it is there- just like the previous CW. That matters to MTH users trying to perform specific bell and whistle sequences.
My gut says that overload works, however, I could also see how you might be able to smoke some thin Lionel lighted car wiring in a derailment. They made and sold both parts of the system- the transformer and the rolling stock, and absolutely, between the thin wiring used for the Fastrack power entry section, to the track joints, to a derailed lighted modern passenger car like a polar express, I'm not 100% sure that the 5 second overload timeout will kill power in time to prevent smoke.
Again, another question asked to me by friends what was the voltage output and as measured, I saw a max of almost 19V, under load dropping to 18.29V.
In theory, overload is kicking in somewhere above 3A and without my good meter handy with an ammeter function, I had to go on measuring voltage across the load and that's not the most accurate method to measure.
My thought is that it's maybe possible with too much accessory + track load to blow the internal fuse that is on the output lead of the transformer before the new control board. I did not try this destructive testing.
I did load the accessory output at 12V setting with the 6 Ohm load, and then applied the 3 Ohm load to the track output at 50% power and tripped the overload red blinking LED and did not blow the fuse and the accessory output and track power both were operating.
I have no concern of it not meeting the labeled 80 watt output. That rating might be combined power and so you may or may not get exactly 80 Watts out of one output or be very close to tripping overload.
I didn't have a fine variable load to achieve that kind of testing.
Also, temperature rise testing since the new one has no fan.
Just for reference, light load testing for temperature of the transformer rise.
I used the accessory output set to 12V RMS unloaded measured with the Fluke 101+ and a small 20ma light bulb just to visually see what the power did or changed.
I used the 6 Ohm load. Ran now for 30 minutes. Transformer is cool to the touch, has not risen in temperature. This was an approximate 24 Watt load. 12v, 6 Ohms, 2A
Pretty impressed that going from the old fan cooled type to this with no vents of any kind, no heatsinks on the FETs, this appears to be a nice cool running transformer.
Again, given I am using the transistors to reduce the output to 12V from the internal 19V, this shows that their switching losses under reasonable loads is very low.
Modern MOSFET tech at work.