| 摘要 |
PURPOSE:To form a current limit oscillating circuit which can control an oscillation by a control signal from the outside, by using a composite constant-current circuit formed by connecting constant-current circuits in cascade. CONSTITUTION:A current I30 determined by a voltage impressed to an input terminal 32 flows to the collector of a transistor (TR)30. In accordance with it, a current I29 flows to the collector of a TR29. Accordingly, a TR33 can be driven into a cut-off state by an input voltage impressed to the input terminal 32. On the other hand, in an oscillating circuit 34, a TR 25 and 33 are incorporated in a feedback loop of the oscillating circuit. In this state, an oscillating operation of the oscillating circuit 34 is driven by a switching operation of the Trs 25, 33, and the oscillation is stopped by cutting off the TRs 25, 33. In this way, a current limit oscillating circuit which can control an oscillation by a control signal from the outside can be formed.
|
