| 摘要 |
PURPOSE:To prevent a voltage over the voltage rating from being impressed to an output terminal of an IC by using a diode to bypass a current flowing to the IC so as to suppress the anode voltage and dividing the voltage by two resistors when the gate voltage gets higher than the gate side main electrode voltage by the ON-voltage of a two-way thyristor and a current flows to the IC. CONSTITUTION:An electric charge stored in a capacitor 13 is discharged momentarily through an inductance 16 and two-way thyristors 14, 15 and the current is going to flow to an output terminal of an IC23. Most current is bypassed by a diode 21 and the anode voltage of the diode 21 is limited to a voltage being higher than the power voltage VDD by nearly 0.6V. The voltage of 0.6V is divided by a 2nd resistor 26 and a 3rd resistor 28 so as not to be impressed to the output terminal 24 is the IC23, and the resistance is selected so that the voltage does not exceed 0.3V over the power voltage VDD. Thus, the latchup of the IC and malfunction are prevented and the 2-way thyristor is driven by using an output terminal with a low dielectric voltage with simple constitution.
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