Presentation model assembled!
Trifilar circuit built to spec. 1n4001's sourced from computer cicuit board due to unavailability. One master and one slave. 100ohm resistors with 1k pot.
Will run on as little as one transistor @ 50ma.
2 transistors @110ma.
Sweet spot seems to be around 110-120 ma one transistor and 290-330 ma with both firing.
1 ohm 5 watt resistor shows no more than .3 volts across it, and as little as .02 v at minimum draw. At current sweet spot it reads .16v with both transistors firing. More accurate readings awaiting arrival of a analogue multimeter. Laser tacho and new 12 7.2ah batteries to follow shortly.
I found the pot useful in getting the wheel up to speed then dropping the amp draw down while maintaining and even increasing speed. Its a little harder to start on the sweet spot and get it up to speed otherwise. Rotor is quite heavy, over 1500 grams and only 300mm diameter.
