| 摘要 |
<p>PURPOSE:To take a measure against reverse connection of a power source without increasing the potential difference between the input and the output by connecting a diode, which is formed by connecting commonly the base and the collector of a PNP transistor TR, in the forward direction between a start resistance and the input side of a control TR connected in series between input and output terminals. CONSTITUTION:A voltage Vin applied to an input terminal 1 is adjusted by the change of the internal resistance of a control TR Q1 connected in series, and a stable output voltage Vout is obtained in an output terminal 2. When this circuit is constituted with a monolithic semiconductor integrated circuit device, a parasitic diode D is formed between a high potential applied layer and an isolation. A TR Q6 functioning as a diode is connected in the forward direction between the input side of the control TR Q1 and a start resistance R1; and since the TR Q6 acts with the polarity opposite to that of the parasitic diode D, the current from a dry cell is stopped by the TR Q6 if the dry cell is connected to the opposite polarity. Further, the output voltage is not reduced because the TR Q6 is not inserted between the input terminal 1 and the control TR Q1.</p> |
