Progress on the BIPM watt balance

Since the beginning of the development in spring 2005, considerable progress has been made on the BIPM watt balance. We have continued the development of a room temperature experiment to test the feasibility of simultaneous force and velocity measurements. We are now able to simultaneously acquire the velocity and voltage of the moving coil and to deduce their ratio. This article briefly recalls the main ideas of the BIPM watt balance and reports the progress to date and the preliminary results.