Operational amplifiers need symmetric power sources typically between 6 and 15 V. In this simple design, we show how to show a whose voltage depends only on the transformer used.
This unbalanced symmetrical source is ideal for powering projects that use operational amplifiers.
In particular we recommend for didactic projects in matrices of contacts for its simplicity.
We should only be careful with its use, possibly adding a 500 mA fuse at the input, since it is neither regulated nor protected.
The source uses full-wave rectification and has an LED to monitor the output voltage.
In figure 1 we have the complete diagram of the source.
Figure 2 shows its assembly using a terminal strip as a base.
The transformer can have from 6 to 12 V of secondary voltage with currents of 200 to 500 mA.
Electrolytes are for 16 V and 1N4002 or even 1N4004 diodes.
The LED can be any ordinary.
Material list
D1 to D4 - 1N4002 or 1N4004 - diodes
LED - common LED of any color
T1 - Transformer - see text
S1 – On-Off switch
C1, C2 - 1000 uF - electrolytic
R1 - 3k3 ohms x 1/8 W - resistor - orange, orange, red
Several:
Power cable, wires, mounting box, solder, etc.
