| 摘要 |
PURPOSE:To prevent chattering at the output side of a voltage comparator by providing a series circuit comprising the 1st resistor and a capacitor, a diode connected in parallel with the 1st register of the series circuit, the 2nd resistor and the voltage comparator obtaining a chattering less signal from the output terminal. CONSTITUTION:A capacitor C repeates charging/discharge in time constants taua, taub for a Tc where chattering exists and a voltage VB at an input terminal B of the voltage comparator circuit COMP is shown in solid lines in Fig. (b). Thus, in adjusting the time constants taua, taub so that the time T when the switch SW is changed over until a voltage VB at the input terminal B of the voltage comparator circuit COMP reaches a comparison voltage VA at an input terminal A of the voltage comparator circuit COMP has the relation of T>>Tc, an output voltage Vc of the voltage comparator circuit COMP is immune to the effect of chattering as shown in Fig. (c). The charge/ discharge circuit comprising the capacitor C and the resistors Ra, Rb and the voltage comparator COMP are combined in this way, the path for charge/discharge is changed by connecting a diode D in parallel with the resistor Ra of the series circuit comprising the resistor Ra and the capacitor C in parallel so as to set optionally the time constant for the charge/discharge. |
