| 摘要 |
PURPOSE:To decrease the loss at a light load by feeding back the collector voltage of an output transistor (TR) in a switching amplifier supplying a switching output to a load having a large fluctuation. CONSTITUTION:The prescribed constant current IX of a signal source 1 is turned on/off according to 0 and 1 of a pulse Pw. A part of the current IX from the signal source 1 is a current I1 and fed to the base of a transistor (TR) Q1, current amplification is applied by TRs Q1, Q2 and a current I0 is supplied to a load R. In this case, even when the load R is heavy while the TR Q2 is not saturated sufficiently, since the collector voltage E0 is high, the base potential of the TR Q4 is high and the emitter current I4 is small. Thus, the base current I1 of the TR Q1 is increased and the base current I2 of the TR Q2 is larger, then the TR Q2 is saturated sufficiently and the load R is driven by a sufficiently larger current I0. |
