| 摘要 |
PURPOSE:To simplify the circuit constitution, by carrying out the switching action with two units of diodes and furthermore forming the switch control circuit with one unit of transistor. CONSTITUTION:The transistor Q3 is turned on when the input terminal 2 of switch control signal is opened to the earth. Thus the switching diode D10 is turned off with the diode D11 turned on respectively. As a result, only the AFC control voltage supplied from the AFC control voltage generating source S2 is delivered through the output terminal C. When the terminal 2 is short-circuited to the earth, the transistor Q3 is turned off. Thus the switching diodes D10 and D11 are turned on and off, respectively. In this case, only the AFC control voltage supplied from the generating source S1 of AFC control voltage is delivered through the terminal C. |
