PURPOSE: To make it possible to adjust the effective drive voltage upon a liquid crystal display and to facilitate the circuit of an electronic analog display device by specifying the connection of a main power source so that one switch element may always be driven under inconductive conditions.

CONSTITUTION: Variour physical properties acting as a display information source are converted by a sensor 5 into electric signals, which are further converted by an A/D converter 6 into coded digital signals so that decoded signals are generated on one line 72 corresponding to the input digital signal value within the output lines 70 to 7n of a decoder 7. The resultant signals are fed to a switch element S2 to drive the latter under its inconductive condition. An AC voltage is impressed from its power source 12 upon the liquid crystal layer between the display segment electrodes B1 and B2 of a liquid display device 10 and a common electrode C, but no voltage is impressed upon the liquid crystal layer between the other display segment electrodes B3 to Bn and the electrodes C. As a result, the optical characteristics of the liquid crystal layer is varied at the portion corresponding to the electrodes B1 and B2 so that the display of a bar graph is accomplished.