CURRENT PROTECTION DEVICE WITH DEPENDENT TIME LAG ON HERMETIC CONTACTS Russian patent published in 2008 - IPC H02H3/08 

FIELD: electrical engineering.

SUBSTANCE: current protection device with dependent time lag on hermetic contacts has first and second hermetic contacts, first and second binary counters and an actuating device. The device also has a driving oscillator, first and second AND elements, first and second DELAY units, first, second, third and fourth read-only memory elements permanent storage unit (PSU), max-selector, third and fourth binary counters, first, second and third decoders, a comparator, OR element, digital display and a switch. The first (second) DELAY unit is in form of serially connected third (fourth) AND element, fifth (sixth) binary counter and first (second) binary-to-decimal decoder.

EFFECT: provision for cutting off short circuit current, flowing along current conducting wires of an electric installation without current transformers, with time lag dependent on current.

2 cl, 16 dwg