| 摘要 |
PURPOSE:To reduce the current consumption in a no-load mode by detecting and feeding back the output voltage via a control circuit consisting of resistances and transistors and controlling the current supply value of a line in accordance with the output voltage. CONSTITUTION:A resistance R1 and a pnp transistor (TR)Q1 are connected in parallel between terminals 9 and 1. The collector of an npn TRQ2 is con nected to the base of the TRQ1 and the collector of a pnp TRQ3 whose emitter is connected to the terminal 1 through a resistance R2 is connected to the base of the TRQ2. Then a capacity C1 is connected between the emitter of the TRQ3 and a terminal 2. In case the DC voltage produced between terminals 1 and 2, i.e., the output voltage Vreg is increased, the base current of the TRQ1 is reduced and therefore the voltage Vreg is also reduced. While the base current of the TRQ1 increases when the voltage Vreg decreases and therefore the Vreg increases. In such a circuit operation, the voltage Vreg is kept at a fixed level. |
