I'm developing a circuit that will run some LEDs (for indoor lighting) powered off some batteries. What I don't want to do is just hook up the batteries to the LEDs, because this will deplete the battery charge too quickly.
To solve this problem I thought of driving the LEDs with a current that I could regulate. To do this, I thought of using a zener diode and an NPN BJT. However, when I thought about it, I'm not sure this is such a good idea.
The total battery voltage is going to vary between about 3-4 V. The LEDs are 3.2 V. If I have a BJT, won't the voltage drop across it make the LEDs dim?