One-Zener Precise Limiter


Posted on Sep 25, 2012

A limiter circuit that requires matched zener diodes can instead use one zener with a full-wave diode bridge. The


One-Zener Precise Limiter
Click here to download the full size of the above Circuit.

circuit"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 circuit, four single controlled-drop diodes and four ordinary diodes gave about the same accuracy (better than 0.5%). 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 circuit 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 circuit adequately and response is orders of magnitude faster than conventional circuits. Moreover, it"s limited primarily by the op amp"s slew rate.




Leave Comment

characters left:

New Circuits

.

 


Popular Circuits

12V Halogen Dimmer
Random Musings
Oscillators and Triggers
12V to 5V 3A DC converter step down Regulator
8PhotoNonInverting
Coolant Alarm
new laser warning sticker
Sensor Circuits
555 IC Water Level Sensor/Detector Alarm
Sound pretty inexpensive bed HI-FI circuit



Top