Dual power supply circuit

The preamplifier in the power amplifier circuit is generally powered by dual power supplies , that is, symmetrical positive and negative power supplies . When making amateur production, x will
encounter unavailable dual power supplies, which brings difficulties to production. This article introduces the use of TDA2030 to convert single power supply into dual power supply to supply power to the preamplifier
NE5532. The circuit is shown in the figure. '
    The TDA2030 (ICl) is a high efficiency operational
amplifier that utilizes its complementary outputs. The unipolar power supply can be
converted into the required bipolar power supply. In the figure
, Rl with equal resistance values ​​should not form a voltage divider.
The midpoint of the voltage divider is connected to the non-inverting input terminal of the IC1 operational amplifier
, and IC1 is connected as a voltage follower, so that the "o"
terminal and the "0" terminal The potentials are equal. The "0" terminal is also a virtual ground
. It is completely isolated from the ground terminal of the input power supply.
G and G are the filter capacitors of the positive and negative power supplies respectively.
The positive power supply is output from the "+" terminal of c and added to 1C2
The ⑧ pin of NE5532, the negative power supply
is output from the "one" terminal of the bar, and is added to the ④ terminal of IC2 NE5532. The "0" terminal
is the ground terminal of IC2.
    Since NE5532 has been introduced in previous articles, I will not go into details here. The component values ​​are marked in the circuit diagram. As long as it is made according to the diagram
, it can generally work normally without debugging. However, the single power supply must use a regulated power supply to ensure that the NE5532 can work reliably.