Last week I picked up a K-Line K-0956 Power Chief Transformer. My layout is a small, single-block layout with the accessory tap powering eight LED-generation K-0265 and K-266 switches, three uncoupling straights, an uncoupling/unloading straight, and DIY-LED-lit Plasticville Switch Tower. All but the switch tower are attached the the common via the outer rails, but the switch tower shares the same common as track common.
It was immediately apparent that something was rattling around loose inside. I hooked my common wire up to the variable voltage (top) black output, my track hot to the variable red output, and my accessory hot to the accessory/fixed voltage (bottom) red output. Both my test locomotive, its horn and bell, and the accessories functioned. Oddly though—eerily?—sometimes when I pressed the whistle or bell firmly down all the way, the accessory power would cut out. The variable voltage throttle was a little loose in the casing, and a couple of times when I turned it all the way up, when I got to full-power and was still putting some clockwise pressure on the knob, the accessory power again cut out.
So, I drilled out the rivets and opened it up. First I noticed that the collar screw of the throttle pot was loose—easy enough to address when closing it back up. Then I saw that the shunt resistor connecting the variable voltage hot and common was broken off on one end. There were also a couple of relatively big chunks of what appeared to be hardened glue amber colored, but opaque. These appeared to be what had been rattling around inside.
After diligently cleaning out all the metal flakes from the drilled out rivets and soldering in a new shunt resistor, I closed it all back up. And reconnected it the same way. When I hooked it back up, the same way, the variable voltage worked fine, but the fixed/accessory voltage did not, EXCEPT when I was pressing firmly and completely down the horn/whistle, and/or the bell button. When I did that the accessory power was instantly on.
My understanding is that the Power Chief transformer is internally virtually identical to the CW-80, except that it does not have a fan, and like the second generation of the CW-80s, red=hot and black=common. The late Dale Manquen wrote an article on his website on the first-generation CW-80 in which he describes the transformer as having "pull down outputs." About three-quarters of the way down his article, Dale wrote, "The use of pull-down output prohibits the use of accessories that must be connected to track common, such as 022 switches, cattle and horse corrals and Lionel uncouple/unload tracks."
Even though the K-Line Power Chief had fixed the flaws of the first-generation CW-80, does it still use "pull-down" outputs? My accessories are connected to track common, so does this explain what is going on? Or is it likely that I have a bad chip, bad triac, or other malfunctioning component? (What is a triac?) Any insight would be most appreciated. For now, I am using a second transformer, in-phase, to power the accessories.
TIA,
Matt
