| 摘要 |
PURPOSE:To reduce the power consumption by supplying the output voltage of a load circuit to the error input side of a comparator without providing a bleeder resistance to obtain a constant voltage. CONSTITUTION:A constant voltage circuit consists of a comparing circuit 1, a constant current circuit CS1, diodes D1-D6, a transistor TR Q1, etc., and a load circuit RL is used instead of a conventional resistance for negative feedback (bleeder resistance). A voltage V2 is obtained by the constant current circuit CS1, etc., and this voltage V2 is supplied to the comparing circuit 1 as the reference voltage, and an output voltage V0 is varied in accordance with the change of the load circuit RL and is compared with the reference voltage V2. As the result, an output current I3' of a TR Q4 is controlled, and TRs Q6 and Q7 are operated as an output circuit as well as a negative feedback circuit. Thus, the constant voltage output V0 is obtained, and currents I1-I3 are about 100muA to reduce the power consumption. |
