Lasted edited by Andrew Munsey, updated on June 15, 2016 at 2:02 am.
This is 1.1kW motor wired to 230VAC 50Hz Rotoverter (rotoconversion mode) running at 60VAC. (Rotoconversion effect is present only at 1/4 nominal voltage)
Current relay is "home-made" using toroid trafo (a cheap way to do it!!!).
Toroid trafo's primary is 2 turns of wire, which creates proper impedance match to connect relay at certain amperage threshold
Trafo's secondary is standard output 14VAC -> full wave rectifying bridge -> DC -> 1500uF capacitor and standard 12V 40A relay. No resistors were used, however you may use 47ohm resistor or potensiometer in series to relay for tuning.
If the current exceeds ca 5A the relay is turned on and starting capacitor is connected. After the required RPM has reached the current decreases below the threshold and starting capacitor is disconnected.
(February 27, 2005) "handsfree" setup is for starting the motor with current relay"
starting start capacitor using current transformer ('hands free')
"this is my trick to use 'current transformer' to connect the start cap automatically by sensing the current"
"I used the motor wired to 230VAC and run it from 60VAC. That is why caps were relatively big."