How to get negative voltage from positive voltage power supply, positive voltage to negative voltage method diagram

    This circuit diagram shows how to get a negative voltage from a positive voltage supply. Another advantage of this circuit is that the negative voltage can be used along with the original positive supply to simulate a dual supply. This circuit is based on the timer IC NE555. The NE555 is wired as an astable multivibrator and operates at about 1KHz. Square wave output (if located at pin 3 of the IC). During the positive half of the square wave, capacitor C3 is charged through diode D2. When the output of the IC is zero, C3 is discharged through diode D2 and capacitor C4 is charged. Therefore, the voltage at the junction of D1 anode and C4 cathode will always be negative with respect to ground.

    Assemble the circuit on the Vero board.

    IC1 must be mounted on the bracket.

    C3 and C4 must be rated for at least 25V.

    Do not connect a load that consumes more than 50mA.

    The negative voltage output will always be a few volts below the positive supply.

    Diagram of the method of converting positive voltage to negative voltage

    Method 1:

    As shown in the figure above, the voltage doubler rectifier method is used. After the 5V, 1KHz sinusoidal signal is amplified by the transistor push-pull, the required negative voltage is obtained by voltage doubler rectifier! (+5V becomes -4V)

    Method 2: 34063-DC-DC conversion method (using the voltage reversal principle of the switching power supply principle) Please refer to the MC34063 boost circuit for the circuit diagram, and then reverse the required voltage

    Method 3: LM317+LM337 single-turn dual-voltage method