I am an inventor. I was known as the black Thomas Edison. Many of my inventions were sold to the newly founded Bell Telephone company. Not counting the many inventions that I sold to other companies, I hold over 50 patents to my own credit.
I am a contemporary of Alexander Grahm Bell and Thomas Edison. I made many modifications to Bell's telephone. I modified the telegraph device so that a moving train could receive messages by telegraph.
I invented a controller for servo motors. At the time that I invented this device, I had no way of knowing that the servo motor would be used in computer print heads and robot arms in the future. Can you guess who I am?