Look at the schematic to better understand. We have a pendulum that can swing. With coils on the top and bottom of the pendulum. The coils are wired in reverse on each coil. As the top coil approaches the top right magnet it produces electricity which is sent to the bottom coil,, energizing it making it attract to the magnet on bottom left. This pulls the pendulum just enough to the bottom left to give it enough energy added to its swing to keep it going. Perhaps something like this made correctly would work for a perpetual motion machine.