1 and 2 are darlington NPN, 3 is PNP.
3 with 1 & 2 form a peuso PNP which have large beta and can handle larger current.
4 is common NPN and 5 is resistor to limit base current to 4.
You can add some capacitor between opamp output and -ve input to keep loop stable.
1 and 2 are darlington NPN, 3 is PNP.
3 with 1 & 2 form a peuso PNP which have large beta and can handle larger current.
4 is common NPN and 5 is resistor to limit base current to 4.
You can add some capacitor between opamp output and -ve input to keep loop stable.
5- is not very important by it can supply the maximum current base.
1- must be chosen so that to deliver max power and current when vin=40 volt and vout =0 and suppose iout =1 amp the trasistor 1 must Ic=5amp and Pt=2.5*40*1=100w such as 2n3055
2- must be drive the base of 1 if beta are 20 for 2n3055 the base current is 1amp/20=50ma so this transistor such as bd139
3- must be chosen so that drive the base of 2 so it bc237 pnp transistor
4-bc547
5- is not very important by it can supply the maximum current base.
1- must be chosen so that to deliver max power and current when vin=40 volt and vout =0 and suppose iout =1 amp the trasistor 1 must Ic=5amp and Pt=2.5*40*1=100w such as 2n3055
2- must be drive the base of 1 if beta are 20 for 2n3055 the base current is 1amp/20=50ma so this transistor such as bd139
3- must be chosen so that drive the base of 2 so it bc237 pnp transistor
4-bc547
O....thanks a lot~~~
But bc237 is a NPN transistor!!
Then, how to add anything to stable this circuit and accurate of the DAC input effect the output??
what is the value of resistor to limit base current to bc547
may I put 2K??