| 摘要 |
PURPOSE: To detect the timing when the level of a DC voltage changes by a simplified circuit. CONSTITUTION: An input voltage 3 is guided to a base of the detection circuit via a first differential circuit 11. A first load resistor R4 is connected to a collector which has a first transistor Q1 having a bias set at an A-class operating point. A collector of the first transistor Q1 is connected to the base via a second differential circuit 12. An emitter of the detection circuit is connected to the ground. A second transistor Q2 connected to a second load resistor R7 is set at the collector. Moreover, the detection circuit has a diode D1. One terminal of the diode D1 is connected to a base of the second transistor Q2, while the other terminal is connected to an emitter of the second transistor Q2. A current is thus supplied in a direction opposite to a direction of a base current in the second transistor Q2. |
