| 摘要 |
PURPOSE:To enhance the use rate of transistors without increasing the circuit loss, by limiting respective maximum collector currents of main control transistor which are connected in parallel and by eliminating a circuit for balancing collector currents. CONSTITUTION:A resistance R6 and a transistor TR2 are a collector current detector and a current limiter for a main control TR1 respectively. A resistance R7 and a TR4 are a collector current detector and a current limiter for a main control TR3 respectively. A resistance R2 supplies the base current to the TR1, and a resistance R8 supplies the base current to the TR3. In the normal operation state, since current detectors R6 and R7 function as series resistances for balancing currents, collector currents of main control TRs are balanced in a certain degree. A maximum value of the collector current of each main control TR is limited to 1/2I0(max). I0(max) is a maximum output current of the power source. |
