i choose 2N2222 transistor since it can handle the load i need (up to about 500 mA).
but i don't know if its suitable for board or not since my signal voltage is 1.8 and load is 12v 120ma .
so according to equation on the https://www.electronicspoint.com/resources/using-a-bipolar-transistor-to-turn-a-load-on-and-off.30/ article
R=((V-VBE)*hfe/(Iload*n)
when
V(signal voltage)=1.8 (red diode voltage on the board)
VBE=0.8
hfe 50 when ic =150
Iload = ic = 150
n = 3(i dont know exactlly)
so R will be 111ohm and i choosed 100ohm resistor for it.
if i'm wrong correct me please.
but i don't know if its suitable for board or not since my signal voltage is 1.8 and load is 12v 120ma .
so according to equation on the https://www.electronicspoint.com/resources/using-a-bipolar-transistor-to-turn-a-load-on-and-off.30/ article
R=((V-VBE)*hfe/(Iload*n)
when
V(signal voltage)=1.8 (red diode voltage on the board)
VBE=0.8
hfe 50 when ic =150
Iload = ic = 150
n = 3(i dont know exactlly)
so R will be 111ohm and i choosed 100ohm resistor for it.
if i'm wrong correct me please.