| 摘要 |
PURPOSE:To prevent the destruction due to thermal runaway, by connecting one end of a load connected to a collector of a horizontal drive transistor(TR) to a common connecting point of plural resistors and cutting off the TR with a voltage drop in a resistor at the thermal runaway of the horizontal drive TR. CONSTITUTION:The horizontal drive TR 1 is connected to an output terminal 16, and a horizontal output TR 3 of the next stage is connected to the TR 1 via a drive transformer 2. If the TR 1 runs away thermally, its collector current IC is increased and a voltage drop V=ICR1 at a series resistor 25 is increased, then a voltage at an input terminal 27 of a regulator circuit 14 is dropped. An output of a pre-stage 13 is decreased attended with it, and an output current of a horizontal output TR 3 is decreased. Then, the collector current IC of the TR 1 is increased and a potential VP at a terminal 27 approaches an earth potential, then the TR 1 is cut off, allowing to prevent the destruction due to thermal runaway in advance. |
