| 摘要 |
PURPOSE:To solve the unsteadiness of the volume by producing the fixed voltage level in the pure electronic way by plural number of the reference constant current source and the current adder circuit. CONSTITUTION:The up- or down-pulses are applied to shift registers S1-S4 to secure the prescribed value. In this instant, the ''H'' levels of registers S1-S4 are corresponding to ''ON'' for switches Q3-Q6 corresponding to one bit of the shift register. The resistances provided to switches Q3-Q6 function as the weighing to the current which flows to each switch. Thus the current corresponding to the ''ON'' switch flows to transistors Q7 and Q8. As a result, the voltage of the prescribed level occurs across resistance R17. With this voltage the electronic volume is formed. Thus the steady volume can be formed with no mechanical part. |
