| 摘要 |
PURPOSE:To reduce the cost by providing a semiconductor switch which opens and closed a contact at a positive and negative power source in a controller, and providing an operational amplifier which proportionally integrates the opened or closed voltage in the amplifier, thereby forming a simulator circuit with less number of parts. CONSTITUTION:Semiconductor switches 19 are respectively connected with control transistors 18 in a controller 17, and contacts 19-1a, 19-2a are connected between a power source and the input resistor 20 of an operational amplifier 24. The amplifier 24 has a gain regulating feedback resistor 21, and an integrating capacitor 23, a phase inverting operational amplifier 28 is formed of a feedback resistor 26, thereby forming a simulator circuit. Thus, a control signal is applied from the transistor 18 to the switched 19, and the input pulse-width- modulated is integrated by the amplifier 24a and the capacitor 23 by opening and closing the contacts 19-1a, 19-2a. this is inverted by the amplifier 28 of next state to obtain a waveform equivalent to the output voltage.
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