Electronics 1914: Bosch invent the electric starter motor

In the first of a series charting events in electronics and technology from 1914, we make a start - literally - with one of the great automotive innovations. 

It is a romantic image from the early days of motoring. Straw-hatted chaps and elegantly turned out ladies stooping over the crank handle at the front of the car, waking their futuristic beast to life.

Yet in reality it was a hard, dirty and sometimes dangerous job. 100 years ago this month, Bosch delighted all automobile owners and chauffeurs when it demonstrated the world's first safe, commercially viable electric starter motor.

The man responsible was Gottlob Honold, lead engineer at the German company. Honold was a legend in the motoring world after inventing the high voltage magneto ignition system in 1901 - effectively, the spark plug that enabled the petrol-fueled engine to become the automobile standard.

Other manufacturers had worked at developing an electric starter motor, but none were suitable for mass production or met safety standards. Safety was a key element - the hand crank had a tendency to slip, or make the engine kick back and spit the handle back and hit the starter. Robert Bosch (1861-1942), who had already built the company he founded into one of the world's first multinationals, with factories and offices in five continents, was determined to develop a solution that could be mass produced and used in his cars.

Honold's starter motor could be operated by a foot pedal, using electrical power from the car battery. The battery was part of the lighting system Bosch had developed in 1913, which for the first time had given drivers enough illumination to drive in the dark without draining the car's electrical system. "The starter motor is typical of the products Bosch launched in the early days of motorization", said Ulrich Kirschner, president of the Bosch Starter Motors and Generators division. "All of them were designed to eliminate shortcomings in function, operation and safety."

The first electric starter motor weighed 10 kg and delivered just 0.6 kilowatts of power. Today's equivalents weigh between 1.9 and 17 kg and produce an output of between 0.8 and 9.2 kilowatts.

Production of the Bosch starter motor began at the company's plant in New Jersey later in 1914. By the mid-1930s 550,000 units had been sold.

Although the magneto ignition system was to be used widely in German military vehicles and aircraft during the Great War, Robert Bosch himself found war abhorrent. Charities benefited from the profits the company made (although Bosch assets in the US were seized after the war) and during the Second World War Bosch employed Jews at a repair workshop in Stuttgart to save them from the Nazi regime.

Bosch of course went on to become one of the world's leading manufacturers of automotive parts, electrical appliances and power tools, and a wide range of Bosch products are available at Rapid.