| 摘要 |
PURPOSE:To avoid the effects to a power supply circuit even though the output flyback line of a power supply circuit of the low voltage and small current is equal to that of a power supply of large current, by detecting the potential directly from a part (e.g., the terminal of package) requiring a stabilized power supply and controlling the detected potential to a prescribed level. CONSTITUTION:The voltage levels of both terminals GM and VRM are divided by the resistances R6 and R7, a variable resistances VR1 and resistances R4 and R5 respectively to a stabilized power supply 12. A comparator 14 amplifies the difference of those input voltage levels and applies it to the base of a transistor TRQ1 as the reference voltage. Then the current of the emitter of the TRQ1 as the reference voltage. Then the current of the emitter of the TRQ1 is controlled so that the potential difference between both terminals GM and VRM is equal to a prescribed level. The larger the gains of the comparator 14 a level the more approximate to a constant level of voltage decided only the resistance level in a voltage divider 13 and the levels of resistances R1 and R2 in the 1st stabilized power supply 11 is secured for the voltage of a power supply circuit.
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