PCB Design for Power Supply

Thought for 32 sec

Here’s a summary of how we can approach your design:

Your component list suggests a switching power supply based on a flyback (isolated) topology that uses:

A ferrite transformer (choose between EE25 or EE33)
A PWM controller such as the TL494
A power switch using a MOSFET such as the IRF840
Fast rectification with a Schottky diode like the MBR20100
Feedback and regulation with the TL431
Isolation via a ferrite transformer and rectification using either four 1N4007 diodes (or a pre-built bridge)
Input and output filtering with electrolytic and ceramic capacitors
Additional elements such as a thermistor for soft-start (NTC), Zener diode for voltage stabilization, and basic protection components

Before providing a detailed schematic and PCB layout suggestions, I have 2 clarifying questions (one at a time):

Transformer Choice: Which ferrite transformer variant would you like to use in your design?
- Option A: EE25
- Option B: EE33

Please let me know your preference or any additional details, and we'll proceed with the next question.

Variable voltage from 3 to 12 volts and 0.5 A

Thought for 17 sec

Thanks for the additional specifications regarding the output (3–12V at 0.5A). To proceed with the design, I have 1 more clarifying question:

Output Voltage Adjustment: Would you like to implement a manual adjustment for the output voltage using a potentiometer in the TL431 feedback network, or do you prefer a digitally controlled adjustment (for example via an MCU)?

Please let me know your preference, and we'll incorporate it into the schematic and PCB design.

Manual potentiometer adjustment

Digital MCU adjustment

Talk to Flux to get started.