A line of standard and custom-designed toroidal step-down control transformers promise less heat generation and smaller size compared to conventional toroidals. With minor losses under no-load and 90% of the total losses in the copper wire under full load, the temperature rise at half the load drops to 25% of the temperature rise at full load. Depending on the transformer used, cooling fans might be eliminated. A 1 kVA transformer measures 163 mm x 84 m and weighs 7.7 kg. Input voltages of 120, 208, 240, 480 and 560 Vac single-phase, 50/60 Hz are available with output voltages of 48, 24 and 12 Vac. Standard transformers have power ratings from 50 VA to 3 kVA. Custom versions are available at no or little price difference. TOROID CORP., Salisbury, MD. (410) 860-0300.