Hi Guise
I have this circuit, and my main goal is to decide what voltage i should have on the voltage source to reach 15 +-10 % mA through the LED.
I realized some things that i think is correct but other than that I have no idea how to approach the problem.
1. The current through the resistor R1 is similar or equal to the LED current
2. Each diode has 0.7 V
3. I lose 0.7 V when going through the emitter on the transistor.
I would really appreciate if someone could give me any advice or formulas to work with, thanks in advance!
I have this circuit, and my main goal is to decide what voltage i should have on the voltage source to reach 15 +-10 % mA through the LED.
I realized some things that i think is correct but other than that I have no idea how to approach the problem.
1. The current through the resistor R1 is similar or equal to the LED current
2. Each diode has 0.7 V
3. I lose 0.7 V when going through the emitter on the transistor.
I would really appreciate if someone could give me any advice or formulas to work with, thanks in advance!
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