| 摘要 |
PURPOSE:To keep the constant voltage property, by detecting the minimum voltage and controlling the phase angle of a rectifying element in case the smoothness is unsufficient to lose the constant voltage property with a low frequency of about 20Hz when a regulated power supply using the contrl rectifying element is applied with the load of a B-class amplifier, etc. CONSTITUTION:An output voltage detecting resistance R2 out of the resistances R1 and R2 of a regulated power supply that produces the positive and negative voltages is not connected between the output terminals but connected through minimum value detecting circuits 9 and 10 which are provided at the positive and negative sides and detect the minimum value of the ripple voltage of the power supply voltage. The current flowing to the resistance R2 is detected by a current Miller circuit 11, and the both-end voltage of the resistance R1 is compared with the reference voltage produced by a Zener diode D5 to obtain a detection signal. The phase angle control is carried out with this detection signal for both SCR1 and SCR2. As a result, the minimum value of the output voltage including the ripple component becomes constant at all times regardless of the frequency of the output voltage of an audio amplifier, etc. Accordingly the maximum output of an audio amplifier, etc. can be kept constant over the entire range of audible frequency. |
