1 Zener Precise Limiter Wiring diagram Schematic

A limiter 1 Zener Precise Limiter Circuit Diagram that requires matched zener diodes can instead use one zener with a full-wave diode bridge. The schema`s two limits are nearly equal when determined by the same zener—only two pairs of forward diodes need to be matched. For best results, an integrated quad of diodes can be used. But, after testing the schema, four single controlled-drop diodes and four ordinary diodes gave about the same accuracy (better than 0.5%). 

 1 Zener Precise Limiter Circuit Diagram

Because the limiting level can be adjusted, zener tolerance can be adjusted out. Gain stability can be optimized by connecting the inverting input to the first op amp to the output of the second to make the schema inherently unity-gain. 

The zener voltage must be increased to 8.2 V to compensate for the two diode drops. Placing small capacitors across the resistors in the loop stabilized the schema adequately and response is orders of magnitude faster than conventional diagram. Moreover, it`s limited primarily by the op amp`s slew rate.