I have some older MRC tech4 200 throttles and the DC ripple causes annoying buzzing in my HO Kato locos, and only the first 40% of the throttle is usable before the locos run too fast. I've decided I want a simple potentiometer controlled transistor throttle. Voltage source will be a large 6V pure DC battery, output needs to be a variable 0-6 volt pure DC output. That means no DC pulse or PWM systems, and I'm not interested in DCC or dead rail. Load will typically be 50-250 mA, but possible spikes up to 1 amp.

I've nearly completed my benchwork for the new layout! It's been a herculean effort and taken about 3-and-a-half months to get to this point, but I'm very happy with the results. There were a few surprises along the way, (both good and bad) and I'll be sure to share my thoughts in an update video soon. Until then, after the jump is a whole mess of photos I've taken along the way:

Further to my Bluetooth version and great feedback from this site, I have now released an updated design of the DCC system using the ESP32 node MCU module instead of Bluetooth. This allows the user to have more than one mobile phone throttle for club layouts etc.
 

Even though I'm a freelancer and my railroad is a complete work of fiction there are certain things I try to keep era consistent or just "looking right". My little logging and mining line is thought be pretty prosperous so it does have some things you might not see on a smaller line like a 90ft. concrete pit turntable and a tall steel viaduct. They are must haves for me and I don't have a real problem rationalizing them but I still find myself questioning the arrangement above. Right after said steel viaduct, the track plunges into a tunnel.