| 摘要 |
PURPOSE:To enable sure commutation of SCR, by reducing the adverse effect of the inductance component of circuit on the turn-off time of SCR, through the small sized transformer construction. CONSTITUTION:The transformer T2 is made smaller in size by separating it to the transformer T1 giving the back bias voltage to the thyristor CR and the transformer T2 turning on QM giving the base current of a small value to the commutation transistor QM. Thus, no collector current flows to the base current supply winding N21 to reduce the adverse effect which lowers the back bias of the thyristor CR due to the inductance component of the circuit. Accordingly, sure thyristor commutation can be made by the commutation transistor QM. |
