On Thursday 28 August 2008, Jesus Genicio wrote: > Vcc ( 1 0 ) DC 5. > Vin ( 5 0 ) PULSE iv= 0. pv= 5. delay= 1. rise= 0. fall= 0. > width= 2. period= 4. > Rc ( 1 8 ) 122. > Rb ( 5 2 ) 12.K > Rled ( 8 3 ) 121. > Q1 ( 3 2 0 ) Q2N2219A area= 1. > > The result is correct: > > gnucap> tran 0 2 0.1 > #Time V(5) V(1) V(Rled) >......... > 1.3 5. 5. 2.4256
> Rled must be one led. > > If i change Rled for a diode 1N4004, example. The results is > > gnucap> tran 0 2 0.1 > #Time V(5) V(1) V(D1) >............. > 1.3 5. 5. 0.74569 > 1.4 5. 5. 0.74569 > 1.5 5. 5. 0.74569 > 1.6 5. 5. 0.74569 > 1.7 5. 5. 0.74569 > 1.8 5. 5. 0.74569 > 1.9 5. 5. 0.74569 > 2. 5. 5. 0.74569 > > But V(D1) must be 2.42 for light diode. If change Rc, de > V(D1) is equal but vce change... That result is correct for a 1N4004. The key parameter is "IS" (saturation current). To make a model for your LED, make a ".model" where you specify only "IS". Choose the value so you get the correct forward voltage. _______________________________________________ Help-gnucap mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gnucap
