| 摘要 |
PURPOSE:To obtain a certain output level, by controlling the reference voltage applied to the reference transistor base after detecting the collector output of the reference transistor. CONSTITUTION:The voltage at the output point A in a PNP current switch circuit is applied to the base of the reference transistor T2 via the detection transistor T4 and feedback transistor T5. Thus a correction is given to the current I which flows to the transistor T2 to keep a certain level of voltage at the point A. Accordingly a certain output level is obtained regardless of a variance of the current amplification factor of the transistor T2. |
