Over a year without posting anything! Disgraceful - dunce's cap firmly on.
Despite the pandemic, lock-downs and other distractions, things haven't developed very much recently. The first lock-down was taken up with long summer walks and home-based IT work for a local charity. By mid-summer it was much too hot to work for long in the loft - 30degC plus some days. Then suddenly it was cold again!
Work restarted before Christmas (2020!) looking at the design of servo poi
The amended objective was to produce a simpler, no-frills DC controller that would meet the original 'anytime anywhere' requirement, working with either a battery, AC or DC power.
Circuit Design
Starting with the emf-sensing feedback circuit used in Part 1, I removed the integrator and schmitt trigger U1 leaving just U1b as a simple non-inverting amplifier. The output driver Q1 - a cheaper and more easily obtainable BD243C - is included in the gain loop to ensure good output vol
Circuit Design
As described in "A Test Track in N - 4: electrics" I started with an emf-sensing feedback design by Jonathan Scott (www.scottpages.net/UniversalTrainController.html second circuit from top). It was intended that the controller would be powered from AC, DC or battery to enable my N test track to be used 'anytime anywhere'.
Construction
I made a few small changes to Mr Scott's original circuit:
C3 to 3uF to reduce inertia on a small layout
