Electronic – Combining buck and boost converter with a single potentiometer

boostbuckpotentiometerpower supplyswitch-mode-power-supply

I'm designing a buck boost converter for a simple variable power supply by connecting a boost(LM2577) converter circuit and a buck(LM2596) converter circuit in series. They each have a potentiometer to control the feedback pin. Is there anyway where I can combine both the potentiometers into one?
Plus, I do not want to get a buck-boost converter module because from where I from its really expensive.

Edit: The 3 euros buck boost converter has low power and after conversion rate in my country it's not worth it since I have the individual modules already. Regarding the power rating, the input will be 12V and have an output range of 1-28V 3A.

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These are the images of the buck boost converters respectively.

Thank you!

Best Answer

I doubt that you really need 2 potentiometers in the first place. Keep the boost (first stage) at fixed output voltage. Control the buck (second stage) with one potentiometer.