Display unit of tachometer for automobile.

摘要

A display unit of tachometer for automobile comprising an engine revolution operational circuit capable of transmitting output signals by operating number of revolutions of engine from input ignition pulse signals, a warning revolution decision circuit connected with said operational circuit, a critical revolution decision circuit, a bar graph decoder, a driving circuit, and a display device of bar graphic displaying provided with necessary number of segments, whereby said display device constantly displays warning number of revolutions of engine by selectively driving only the segment displaying desired warning number of revolutions and displays actual number of revolutions of engine by driving all the segments corresponding to number of revolutions other than said actual number of revolutions, or displays number of revolutions exceeding said warning number of revolutions by stopping said driving of the segment corresponding to said warning number of revolutions when said number of revolutions of engine exceed said warning number of revolutions and further displays critical number of revolutions with the flickering of the display device by driving intermittently each segment when number of revolutions of engine reach preset critical number of revolutions.