| 摘要 |
PURPOSE:To reduce current consumption in the cut-off time of an output current by providing a switching transistor between the base and emitter of a constant-current transistor and then by applying a constant voltage and control signal to both bases via resistances. CONSTITUTION:When control signal Defeat is at the earth level, transistor TrQ10 is OFF and constant-current transistor TrQ9 generates a constant current of I0= (VB1-VBEQ9)/R5. Then, when control signal Defeat is made high in level, TrQ10 is sturated and TrQ9 turns OFF to cut off an output constant current. Namely, setting adequately the values of resistances R6 and R7 reduce the current consumption. |
