Cape Innovator Takes up Thomas Edison’s Torch and Invents, Patents a New Universal Socket

by Mwangi Githahu / Cape Argus

“I was motivated by the fact that the design of Thomas Edison’s screw socket hasn’t changed in 140 years since its invention.”

Photo: Inventor and innovator David Harte tinkering with a plug in the garage where he worked on his invention. Picture: Mwangi Githahu/Cape Argus. 

Harte’s invention has now been patented in the biggest markets in the world – these are the US, Australia, China, India and, of course, South Africa. The invention, which is ready for market, means Harte’s name can stand alongside that of Mark Shuttleworth, who created the Ubuntu open-source Linux operating system that helps connect everything from drones to thermostats to the internet.

Harte’s light bulb moment occurred to him while sitting in a dark prison cell in Mauritius where he was serving a 9-year sentence for smuggling 500 grams of heroin into the country.

“My life had gone to pieces after my second divorce and I had been reduced to living in a backpackers’ hostel and was desperate.”

Photo: The three different types of bulbs that can fit Harte's socket. Picture: Mwangi Githahu/Cape Argus.

He was on his second drug couriering mission to Mauritius when he was caught in a police drug bust. His time in the prison is now the subject of an episode of the NatGeo TV series, Locked up Abroad. Harte was a model prisoner and turned his life around by teaching basic computer lessons to fellow inmates. Because his lessons were such a success, he earned himself a few privileges, such as a light in his cell so he could read at night.

Photo: Harte with his twin brother Harold in whose garage he worked on his invention. Picture: Mwangi Githahu/Cape Argus.

One night, the light bulb expired and when he obtained a replacement, it was the wrong sort of bulb.

“I thought to myself: why hasn’t anyone come up with a light bulb that can fit any socket?”