| 摘要 |
PURPOSE:To obtain the input burst signal in a faithful way and at the same time using the burst signal also for the purpose of recording and reproduction for the burst gate amplifying circuit which is used to the color video tape recorder or the like. CONSTITUTION:When the gate pulse is supplied in a high level to the burst gate pulse input terminal GP, the transistor TrQ11 is turned on with the TrQ12 turned off each. As a result, the TrQ9 and Q10 forming the constant current source are turned on. And if the TrQ11 base becomes to a low level to turn off the TrQ11, the TrQ12 is turned on with the TrQ9 and Q10 turned off each. On the other hand, the TrQ1 and Q4 are turned on in the 1st state under which the side of the switch signal input terminal S1 and the side of the switch signal input terminal S2 are turned to a high and low level each for the TrQ1-Q4. On the contrary, the TrQ2 and Q3 are turned on in the 2nd state under which the sides of S1 and S2 become to a low and high level each. |
