| 摘要 |
PURPOSE:To obtain a circuit simple in configuration, small in number of parts and advantageous to lower its cost by giving threshold value characteristics and clip characteristics by a common emitter type transistor amplifier for signal amplifying function and performing temperature compensation by a diode. CONSTITUTION:In the figure, a resistor 226 is connected between the emitter and earth of a Tr214, and a resistor 227 is connected between Vcc power source terminals. Thus, the voltage obtained by dividing the voltage Vcc by resistance R226, R227 of resistors 226 and 227 is given to the emitter of the Tr214 as the threshold value voltage. At the same time, a resistor is inserted equivalently between the emitter and the earth. A diode 250 is used to eliminate the voltage between the base and emitter and for temperature compensation. Thus, the voltage appearing in the collector of the Tr214 is supplied to the base of a transistor 216 that constitutes a common emitter amplifier circuit. An inversed and amplified signal is generated in the collector as a controlling signal Vo. This signal is supplied to the first grid of the image pickup tube and controls a beam current. |
