摘要 |
PURPOSE:To convert both polarity pulses into a unipolar pulse, by connecting the base of an NPN transistor (TR) to the base of a PNP TR and using the connecting point as a common input terminal. CONSTITUTION:A rectangular wave ea is applied to an input terminal 11 and differentiated at a capacitor 1 and a resistor 2, and a signal ei obtained at the rise and fall of the rectangular wave through the differentiation is denoted as an input voltage signal to a waveform shaping circuit. In the wavform shaping circuit, the base of an NPN TR3 and a PNP TR4 is mutually connected and the said signal ei is inputted to this connecting point. Since a voltage dividing the voltage of a power supply 10 with resistors 8 and 9 is applied to the emitter and base of the TRs 3 and 4 as a reference voltage Vs, the TR3 is conductive at positive pulses of the signal ei, and a voltage drop is produced across a load 5. Thus, a PNP TR6 is conductive and a positive pulse is caused across a load 7. Next, at negative pulses of the signal ei, the TR4 is conductive and positive pulses are produced across the load 7. |