Together with his wife, Rosemary, he founded Bourns in a garage behind their home in Altadena, California.
Marlan Bourns invented and patented the Trimpot trimming potentiometer in 1952. He held over 100 patents.
While studyng for his Bachelor’s Degree in Physics from the University of Michigan, Bourns earned a reputation for being able to translate complex concepts into hardware in the University’s machine shop.
This practical knowledge led to his being selected during World War II for a top secret US Navy programme at the California Institute of Technology that was a key part of the Manhattan Project, although he was not told about the purpose of the programme until after the end of the Project.
When they founded Bourns Laboratories, Marlan designed and built aerospace transducer products while Rosemary handled administrative and sales aspects of the business.
Marlan and a handful of engineers and machinists worked in the garage making products and testing them in Rosemary’s kitchen using her oven and freezer for hot and cold environmental testing.
The breakthrough came when Consolidated Vultee in San Diego placed a large $17,000 order for every product Bourns Laboratories could make, including linear motion potentiometers, vane transducers, accelerometers and bourdon tube pressure transducers.
Bourns products were later used in the Apollo missions to the moon, including the sensor in the joystick control that the pilot used to set the Lunar Landing Module gently down on the surface of the moon and the pressure transducers in the astronauts’ backpacks that regulated their oxygen as they walked on the moon.
The Bourns Foundation has funded a $10 million endowment and supported the Marlan and Rosemary Bourns College of Engineering during its 21 year history.
In 2010 Cal State University, San Bernardino honoured the Bourns family with the Spirit of the Entrepreneur, Lifetime Achievement Award.
Marlan’s wife of 65 years, Rosemary, died in 2012. They are survived by their four children, Gordon, Linda (Hill), Anita (Macbeth) and Denise (Moyles), their children’s four spouses, fourteen grandchildren with eight spouses and six great grandchildren.