| 摘要 |
PURPOSE:To attain the digital setting of upper/lower limit voltages by providing 1st, 2nd D/A converters, an upper limit selection circuit HVG and a lower limit selection circuit LVG. CONSTITUTION:A lower limit voltage VL is outputted from the 1st D/A converter 1 and inputted to an HVG2 together with the input voltage. Then the output voltage v1 is limited by the voltage VL. On the other hand, the upper limit voltage VH is outputted from the 2nd D/A converter 3 in response to a digital setting value VHd. The voltage VH and the voltage v1 from the HVG2 are inputted to the LVG4 and its output voltage is limited by the voltage VH. Thus, the input voltage and the output voltage are limited by the upper limit and lower limit voltages. Thus, the upper/lower limit voltage is easily set or changed digitally by a digital computer or the like. |
