| 摘要 |
PURPOSE:To automatically switch the half-wave and full-wave rectifying functions in response to an input level by providing means for adding the output of an arbitrary Tr to that of the other Tr if the output differences of the two transistors (Tr) constructed in a differential manner exceeds the preset level. CONSTITUTION:The first and second NPN type Trs 1, 2 are connected in a differential type, an AC signal is applied from an input terminal 4 to the base of one Tr1 to obtain an output signal 20 from an output terminal 5. In this case, a resistor 31 is inserted to the collector of the Tr2, the emitter of PNP type Tr32 is connected with the collector of the Tr1, the base of the Tr32 is connected with the collector of the Tr2, and the collector of the Tr32 is connected with the base of the Tr3. Thus, the Tr32 does not operated when the value of the resistor 31 is at a predetermined level or lower signal 10'', but becomes the output 20'' of half-rectification, and the Tr32 operated by the signal 10''' larger than the previous level to perform a full-wave rectification, and is automatically output from the output terminal 5. |
