General Improvement of Control Element of Reverse-Current Cutouts

摘要

An investigation was undertaken to find a means of improving the performance of aircraft reverse-current cutouts. It was decided that, to be satisfactory, an ideal cutout designed for a 28-volt d-c aircraft system should close at a differential voltage between generator and bus of 0.2 volt and open under a reverse-current equal in magnitude to five percent of the generator fullload current. It should operate at the same values for any system voltage between 20 and 30 volts, any temperature between -55C and +70C, and severe conditions of vibration, shock, dust, humidity, and at any altitude up to 50,000 feet. It should be small in size and weight, should be simple and dependable in operation, and have a low power consumption. A circuit is proposed utilizing a permanent magnet control element to trigger a unique thyratron circuit, which, it is believed, will satisfactorily meet all the rigorous conditions imposed, if properly designed from a mechanical standpoint. (Author)