# Voltage Limitter With Op-Amp Comparator

The basic concept used in this **voltage limitter** is D1 and D2 are in pairs on a voltage comparator of the Op-Amp. Application circuit of **Voltage Limitter With Op-Amp Comparator** is often applied to measuring devices such as digital-based analog signal frequency meter or frequency counter. For TTL applications D1 and D2 in series “**Voltage Limitter With Op-Amp Comparator**” can use a zener diode 5Volt to fit the needs of the TTL system. The series “Voltage Limitter With Op-Amp Comparator” can also be used for microcontroller applications as crrosing zero detector circuit for SCR or triac driver.

### Voltage Limitter With Op-Amp Comparator Circuit

In the circuit **Voltage Limitter With Op-Amp Comparator** magnitude above the level of output (Vo) is limited (limitter) by the value attached to a zener diode, zener diode voltage where the value is Vi and the zener diode voltage drop Vd then apply the following formula.

- At the time down to a level Vo negative then D1 becomes forward biased and D2 be a breakdown, then apply the following equation.

**Vo = Vi + Vd1**

- At the time of Vo up to a positive level so that D2 becomes forward biased and D1 breakdown, then apply the following equation.

**Vo = Vi + Vd2**

- So the overall circuit output
**(Vo) is + (Vi + 0.7) and + (½ + 0.7)**

Hopefully this article on “**Voltage Limitter With Op-Amp Comparator**” a little of this can be an inspiration and useful for visitors.