***Threshold Circuit Challenge***

Thread Starter


Joined Jan 6, 2016
Hi All
I am trying to create the following circuit:
I want the circuit to give 5V output if an input voltage is above a certain threshold OR if it is below a certain threshold. If the input voltage is within these two thresholds then the output is 0V. If anyone could give suggestions or point me in the right direction that would be greatly appreciated.

Kind Regards



Joined Jan 15, 2015
You are looking for what is commonly called a "Window Comparator" circuit. You will find examples of various comparator circuits here. Scroll down to the:
Voltage Window Detector Circuit

Comparators with Open Collector outputs such as the LM339 or LM393 must be configured so the both outputs are HIGH when the voltage is within the desired limits. The LM311 comparator can have other output arrangements as it has both an open collector and open emitter on the output transistor.
I suggest you read a little to understand voltage comparator circuits and using hysteresis in such circuits.

Well I see I was slow on that response. :)