watts each. The surface was a Pyroceram ceramic sheet surrounded by a stainless-steel bezel, upon which four magnetic sliders adjusted four corresponding potentiometers below. That design, using no through-holes, made the range impervious to spills. The electronics section was made of four identical modules cooled by a single quiet, low-speed, high-torque fan. In each of the electronics modules, the 240 V, 60 Hz domestic line power was converted to between 20 V to 200 V of continuously variable DC by a phase-controlled rectifier. That DC power was in turn converted to 27 kHz 30 A (peak) AC by two arrays of six paralleled Motorola automotive-ignition transistors in a half-bridge configuration driving a series-resonant LC oscillator, of which the inductor component was the induction-heating coil and its load, the cooking pan. The circuit design, largely by Ray Mackenzie, successfully dealt with overload problems. Control electronics included functions such as protection against over-heated cook-pans and overloads. Provision was made to reduce radiated electrical and magnetic fields. Magnetic pan detection was provided. CT2 was UL Listed and received Federal Communications Commission (FCC) approval, both firsts. Numerous patents were issued. CT2 won several awards, including Industrial Research Magazine's IR-100 1972 best-product award and a citation from the United States Steel Association. Raymond Baxter demonstrated the CT2 on the BBC series Tomorrow's World. He showed how the CT2 could cook through a slab of ice. Sears Kenmore sold a free-standing oven/stove with four induction-cooking surfaces in the mid-1980s (Model Number 103.9647910). The unit also featured a self-cleaning oven, solid-state kitchen timer and capacitive-touch control buttons (advanced for its time). The units were more expensive than standard cooking surfaces. In 2009 Panasonic developed an all-metal induction cooker that used frequencies up to 120 kHz, three to five times higher than other cooktops, to work with non-ferrous metal cookware. Vendors The market for induction stoves is dominated by German manufacturers. Single ring portable hobs became popular in the UK, with prices as low as £30. The European induction cooking market for hotels, restaurants and other caterers is primarily satisfied by smaller specialist commercial induction catering equipment manufacturers. Taiwanese and Japanese electronics companies are the dominant players in induction cooking for East Asia. After aggressive promotions by utilities in HK, many local brands emerged. Their power and ratings are more than 2,800 watts. Some of these companies market in the West. In the United States, as of early