I know this question was asked before, But couldn't understand properly the datasheet reading.
I would like to control
water pump via
Wanted to make sure Im reading the datasheet correctly + Im connecting everything properly.
So if I understand correctly, on the worst case, the water pump will need 6v. so the calculations will be according to
Ipump(max) = 1.8w/6v = 300mA Ipump(min) = 0.6w/4v = 150mA
2N2222 data sheet, figure 11:
Ib = Ic/hfe -> 300m/10 = 30mA R1 = (Vrpi - Vbe)/Ib -> (3.3-0.9)/30m = 80ohm
In order to make sure the water pump will get the current it needs, we will limit
Ic to higher value:
R1=50ohm Ib=(3.3-0.9)/50= 48mA Ic=Ib*hfe= 48m*10 = 480mA
Wanted to ask :
1. Do I read the `hfe` correctly? is it the right value to make sure the saturation? 2. There is a need to connect a diode in parallel to the water pump? resistor in series to the water pump?
Thanks for the guidance.