NOVELTY - After disconnection from normal control (3) a pulse generator (4) sends positive and negative pulses to a motor winding R. The response currents are measured (5) from voltages (Vpr,Vnr) which appear after a fixed time on a neutral resistor (2) and their difference is calculated. Similar differences are taken for the two other windings (S,T) and the three values are supplied to a calculator (6) which uses stored data to deduce the rotor position USE - To find the angular position of electromagnetic motor rotor without collector ADVANTAGE - The method is very accurate and does not require a large number of expensive sensors which introduce an element of unreliability DETAILED DESCRIPTION - INDEPENDENT CLAIMS are made for equipment used with the method DESCRIPTION OF DRAWING(S) - The drawing shows the pulse generator and means of measurement and calculation Neutral resistor (2) Normal control (3) Pulse generator (4) Measurement module (5) Calculator (6) Neutral resistor voltages (Vpr,Vnr) Motor windings (R,S,T)