| 摘要 |
PURPOSE:To obtain a highly accurate test pulse in the side of a light receiving element, by turning an ON-and-OFF display device at frequency not following visual sensation at the time of lighting and easily discriminating the ON-and-OFF signal of the display device and disturbance light in the side of the light receiving element. CONSTITUTION:Electric power to be measured is inputted to an electric power frequency converting circuit 1 to be converted to a pulse with frequency proportional to the electric power to be measured. The frequency of this pulse is divided by a frequency dividing circuit 2 to be converted to the frequency matching with the display unit of a counting displaying device 3 and said frequency is integrated and counted by the display device to display measured electric power. An AND gate 5 inputs the output pulse of the circuit 2 and the pulse with frequency not following visual sensation of an oscillation circuit 4 to output the same to an ON-and-OFF display device 6. The display device 6 performs ON-and-OFF display by the output pulse with frequency exceeding the limit imparting flicker to visual sensation and ON- and-OFF with lower frequency equal to the frequency of the output pulse of the circuit 2 is sensed by visual sensation and the magnitude of electric power to be measured is displayed at a ON-and-OFF speed. |
