Question

Using the circuit in this experiment as a guide, design a 4‐level LED voltage meter. The LEDs should come on sequentially when Vin = 2 V, 4 V, 6 V and 8 V respectively. Include a fully labeled schematic and all analytical derivations.

+15 R1 Vin U1A Rlimiting } R2 am - 15 LED1 +15 U1B Rlimiting R3 - 15 LED2 5 Figure 5. TWO LED level meters.

Answer 1

Here we need to build a 4 level LED voltage meter. Op-camp can be used as a 2V, 4, 6V 8V is the T provide it F IT m Comparator to check where ther Vin crossed respectively, The reference voltage each comparator respective voltage it will on for ie., ev, qv, bv, ev. as we v terminal of op-amp We need to obtain the reference voltages zu, 4v, Bu, 8V from supply isv. by using resistor dividea structures. Let the total sum of resistances of resitors ko divider 5 resistors, ie A 2K resistors and I 7K resistor satisty the purpose of voltage division for references. be 15k. Then by using

15 1k + Vin Riinniting 2K - 15 Rlimiting 2K 15 Reiniting 12K -15 Relimiting - 15 2x