A very simple 5-20V fixed output power supply circuit, which requires very few electronic components and has a very low voltage drop and may provide a maximum output current of 1 A, and reverse voltage protection and peaks of up to 60 V, can be made using this circuit diagram.
This 5-20V fixed output power supply circuit is built using LM2941C integrated circuit manufactured by National Semiconductor.
In circuit, C1 is necessary only if the distance is relatively large filter capacitor.
Output circuit was designed to be stabilized between 5 V and 20 V.
The resistor R1 should not be less than 1 k. The value of R2 can be calculated with the formula:
R2 = R1 (Uout / 1.2751-1) where Uout is necessary voltage output.