In 1912 Charles Arnold and Charles Belling formed Belling and Company making electric fires. Following his release from the army in 1919 Charles Arnold founded 'The Heavy Current Electrical Accessories Company' with Charles Belling as a shareholder. This was later renamed MK Electric. The company developed electrical equipment such as high rated switches and sockets. A portrait of Charles Arnold by May Bridges Lee is held by the University of Bristol.
During World War II, production at the Edmonton factory focused on munitions to help the war effort, but development work resumed in 1945. In the 1950s MK Electric produced a light switch design which is still used today.