| 摘要 |
PURPOSE:To set the hysteresis voltage of fixed width to the integrated reference voltage by adding a working voltage comparator including a constant current load circuit and a hysteresis voltage setting resistance and controlling the working voltage comparator with ON/OFF of said comparator to change the direction of the current flowing to a hysteresis voltage setting resistance. CONSTITUTION:A voltage comparator 7 delivers the output voltage of a low level in case the AC output is larger than the reference voltage at the positive side. Therefore, a switching transistor 14 becomes conconductive. In this respect, an input transistor 28 conducts and a diode 26 and a TR25 are onconductive by setting the comparison input of a voltage comparator 19 is set larger than the reference input decided by an equation. Therefore a constant current I0 of a differential amplifier circuit flows toward the pull-in direction of the circuit 19 via the collector of the TR28 and the hysteresis voltage setting resistance 12. As a result, the reference voltage of the circuit 7 is lower than the integrated output voltage by I0.R0 (R0: resistance value of the resistance 12). |
