| 摘要 |
PURPOSE:To prevent oscillation by a small-capacity capacitor by providing resistances at bases of transistors (TR) so that their voltage drops are equal, and also providing a capacitor which forms an LPF together with one resistance. CONSTITUTION:A resistance R20 is provided in series to the base of a TRQ16, and between the base and collector of TRQ16, a capacitor C2 is provided, thus constituting an LPF for oscillation prevention. To the base of a TRQ15, a resistance R19 is connected so that voltage drops by base currents of both the TRs Q16 and Q15 are equal. Because of the insertion of those resistances R20 and R19, high-precision current detection and limiting operation are secured without exerting any infleunce upon current limiting characteristics. Therefore, the resistances R20 and R19 may have considerably large resistance values. Consequently, the capacitor C2 constituting the LPF together with the resistance R20 may have, for example, <=100pF small capacity value. |
