| 摘要 |
A bipolar voltage detector comprises first and second transistors having emitter electrodes grounded through a first constant-current circuit for a preselected current, third and fourth transistors having emitter electrodes grounded through a second constant-current circuit for the preselected current, and a power supply terminal for a power supply voltage. Base bias voltages supplied to the first and third transistors are rendered higher than those for the second and fourth transistors, respectively. Collector electrodes of the first and third transistors are connected to the power supply terminal. Responsive to a bipolar input signal superposed on the base bias voltages of the second and third transistors, a sequence of output pulses that rise and fall when the input signal exceeds the differences between the base bias voltages of the first and second transistors and between those of the third and fourth transistors is produced as an output signal from those collector electrodes of the second and fourth transistors which are coupled to the power supply terminal. The base bias voltages are preferably derived by potential dividers consisting essentially of resistors.
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