Obtaining two voltages from one rectifier circuit

18. Obtaining two voltages from a rectifier circuit It is difficult to output two voltages from a rectifier circuit or an untapped secondary winding of a transformer, but in some cases it is precisely necessary to do so. The circuit shown in the figure below can output two voltages. One voltage is a bridge rectifier circuit composed of rectifier diodes V1-V4, which outputs voltage U on capacitor C1; the other outputs a voltage that is twice U, or 2U, on capacitor C3. How can I output 2U on capacitor C3? The voltage doubling rectification process is: in the positive half cycle of the alternating current, terminal A of the secondary winding of the transformer is positive and terminal B is negative, and the current charges the capacitor C2 through the rectifier diode V5; in the negative half cycle, terminal B is positive and terminal A is negative. Negative, -U and U are superimposed to charge the capacitor C3 through the rectifier diode V6. Through the common ground terminal, the diode V1 to the A terminal form a closed loop. Repeatedly, a DC voltage of 2U is output on the capacitor C3.