I have a project with arduino. I want arduino gpio open and close 12-14v changable external suply (car electric) with this schematic without zener.
Ekran-g-r-nt-s-2021-02-16-221314 — ImgBB
BC547 works well. Collector voltage changing when arduino pin turns HIGH or LOW. But mosfet is always open.
I checked gate - gnd voltage When gpio Hıgh - LOW 0.18v - 9v so there is a voltage drop from 13.5.
I cant raise gate - gnd voltage near suply voltage. Then I make shortcut gate and suply for a second withoot R10 res. MOSFET closed as I want. But this short cut heated BC547.
I tried some resistors different value but. I cant raise gate voltage. I tried lower r10 res then gate voltage not gone 0v it was 6v-9v wierd. I guess suplly current beat BC547
How can solve this.