SZBK07 DC-DC converter with fine/coarse potentiometers
In this video I show you how to connect four (2 each) potentiometers instead of the original CC and CV potentiometers in order to have a fine and coarse adjustment of the current and voltage. We have to keep in mind that the CV potentiometer acts as a rheostat (variable resistor) and the CC potentiometer acts as a voltage divider. Therefore, I wired the two fine/coarse potentiometers accordingly. This setup allows you to quickly approach the target value using the coarse potentiometer, then further adjust with the fine potentiometer to get the exact value.
Wiring and schematics
Back side of the SZBK07 DC-DC converter. The CV potentiometer is connected as a rheostat which can also be seen by the trace that connects the B and C holes. The CC potentiometer is connected in a normal way, it is used as a voltage divider.
Potentiometer and resistor schematics for the CV potentiometer. This circuit allows you to regulate the voltage on a coarse and fine scale. Only 2 wires are used here.
Potentiometer and resistor schematics for the CC potentiometer. This circuit allows you to regulate the current on a coarse and fine scale.
