| 摘要 |
PURPOSE:To ensure operations, by short-circuiting a silicon controlled rectifying element between the gate and the cathode by the semiconductor switching element connected to the output end of the voltage comparator. CONSTITUTION:The voltage which appears by closure of power source switch 3 not only is subjected to half-wave rectification and voltage division to be applied to the timer circuit consisting of resistance 10, diode 11, and capacitor 12 but also turns on transistor 24 to apply a constant voltage to the gate of PUT20. When the terminal voltage of capacitor 12 reaches the gate voltage of PUT20 after a prescribed time, PUT20 is triggerred, and transistor 20 is turned off, and the current flowed to constant-voltage Zener diode 17 is flowed to the gate of thyristor 6 to open the contact of power source switch 3. |
