PNP

227

05:42:31

PNP

published 10 years ago

thebugger

10 years ago

Limit the base current. You're drawing 1.2A to drive a 20mA LED. You're gonna fry the transistor this way. Just add a resistor from base to ground. Almost any value will do

thebugger

10 years ago

And add a current limiting resistor in series with the LED.

Secuture

10 years ago

A reverse bias potential is required at base to set transistor ground level close to potential drop on led. Curent limiting resistor is not need at colector side only at emiter side. Colector curent will be constant until collector load voltage drop rise above base ground point level. U can also place active supply at colector side eliminating need of base bias.

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