can someone check my math to make sure this wont burn
so if I have the curcuit below with the led needing .02A and having a forwad V of 2 then the resistor connected in series with it should be = (5v-2v)/.02A = 150ohm then if Ic = B*Ib and im using a P2N2222A transistor data sheet with a B around 100 then .02A = 100*Ib then Ib should be .0002A or 200uA then if the switch is on and the V(sat) is 1.2v then the value of the resistor is (5v-1.2v)/.0002A = 19000ohms. right?
so with the vaules inputed it looks like this?
so if I have the curcuit below with the led needing .02A and having a forwad V of 2 then the resistor connected in series with it should be = (5v-2v)/.02A = 150ohm then if Ic = B*Ib and im using a P2N2222A transistor data sheet with a B around 100 then .02A = 100*Ib then Ib should be .0002A or 200uA then if the switch is on and the V(sat) is 1.2v then the value of the resistor is (5v-1.2v)/.0002A = 19000ohms. right?
so with the vaules inputed it looks like this?
Attachments
-
17.7 KB Views: 105