| 摘要 |
PURPOSE:To prevent destruction of a horizontal deflection output transistor(TR) till the circuit reaches a stable operating state after application of power. CONSTITUTION:A protection circuit 15 applies a voltage at an output terminal 17 of a 1st power supply circuit 1 directly to a noninverting input terminal of a comparator 16 and applies the voltage to an inverting input terminal via a resistor 18 and a capacitor 19 is connected between the inverting input terminal and ground. An output of the comparator 16 is at a high level till the voltage across the capacitor 19 reaches the voltage at the output terminal 17 through charging after application of power and then goes to a low level afterward. While the output of the comparator 16 stays at a high level, a diode 20 is conductive and a control current is added to a control terminal 13 via a resistor 21 to control a supply voltage of a 2nd power supply circuit 12. |
