Temporary relief of entropion may be provided by the taping of the lower eyelid to the cheek but the treatment is usually surgical. See ectropion; therapeutic soft contact lens; orthopaedic spectacles; tarsus; trichiasis. cicatricial entropion; involutional entropion See entropion.
A Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages at low currents. Tesla's original circuits as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer.
Tesla invented his resonant transformer, as the Tesla coil is sometimes called, to power a new type of high-frequency lighting system, as his 1891 patent drawing shows. This was the first Tesla coil patent. There followed a series of other patents developing the device.