Use Zener diode to control an LED array


I am trying to use an LED array to indicate a voltage level. For example, if the voltage is 3V, then 1 LED is lightened up. If 4V, 2 are lightened up. If 5V, 3 are lightened up, etc.. My previous design is to use many simple analog comparators to achieve this.

I now somewhat feel that it is possible to achieve the same effect with some Zener diodes. It would greatly simplify my circuit. How may I do it with Zener diodes?

Best Answer

Not trying to ruin the show, but the cheapest STM8 microcontroller would come for $0.5 and perform 10-bit A/D conversions for you. It will run without any external component and the programmer will come for another $3.5, which isn't bad at all.

Why not give it a shot??