🙃it can be done , but do you think he can !

It can be done. Just remove the old TL431 feedback circuit entirely. We'll be replicating its behavior to take control over the power supply. Use a op-amp circuit to amplify and compare current (shunt voltage drops) with the set value. If the current exceeds the set threshold it forwards an "overvoltage" signal, decreasing the voltage and thus current. Once one of the values drops low enough, the circuit assumes there is undervoltage, so it brings the voltage and current back up. Both values can be regulated like this, with the current control having priority. This happens over 60,000 times a second, resulting in precise regulation.

20K

@@t.t.discovers9570 that actually depends on the power supply

i have the 12 volt 40 amp switchers and the value thats in it stock is a 1k variable.

10k

That potentiometer had a small voltage range used for fine tuning from 18 to 27V on a 24V supply, for example. We want the largest range possible, so we connect straight to the voltage feedback circuit. This allows us to regulate down to 3V. But if that potentiometer ever disconnects.. congratulations, you damaged your power supply as there's no voltage feedback anymore, which makes the control circuit think there is low voltage, increasing the pulse width and output voltage which it doesn't detect and this continues until the output capacitors blow up from overvoltage.

Pax pax as my wife say

Where u get a 50k

The older one could just provide a range of 9-14 volts The higher range of the R value the wider voltage range you will get. Yet, i believe it will not be as accurate as the old one

no es que lo hizo variable, es simplemente que cambio el rango de variación. igual si superas el rango de voltaje original de la fuente por mucho se vuelve inestable y cae el amperaje si la quieres fija cambias el variador por una resistencia fija en el valor especificado por la variable y listo. y si es fija de fabrica haces lo opuesto solo debes saber cual es la resistencia la cambias por un variador y ya. en cuestión de fuentes nada es fijo o variable si se tiene el conocimiento para hacerlo.

Yes but the orig pot on the board limited only at 10v to 14.6v

@@smoke_stackz3168 So value of trim should be less than 10k of the new pot.

yes. he just put extention to the trimpot. lol2