Some of the newer ranges- both gas and electric- have automatic temperature control for one or more surface burners or units. Besides convenience, these units make it possible to get more consistent results time after time.
Pickett, Mary S.
"New Ranges Feature - Heat Control for Surface Cooking,"
Iowa Farm Science: Vol. 16
, Article 6.
Available at: https://lib.dr.iastate.edu/farmscience/vol16/iss6/6