Sunday, 29 July 2018

operational amplifier - Taking the absolute value of a DC source (getting the magnitude of the voltage)


I found a circuit online that claimed it was an absolute value circuit, plugged it into the simulator where it worked and tried to implement it on a breadboard. I could not get it to work. So my question is this: How does one take a DC input, like a battery and output the magnitude of its voltage regardless of the polarity of the input?


I want to be able to compare some measured voltage of a 9-V battery to some reference where the polarity of the leads don't matter for someone unknowingly connecting them the wrong way...


EDIT: In order to clarify, I'm just asking how one would go about designing a good absolute value circuit. However, the problem with my circuit might be the parts I used. I know it's wired right because I've done it several times over on the breadboard and get an output that's incorrect, of course. I also have plenty of these ICs and switched them out. Basically I've performed all the debugging you can think of.


My refined question: How would one go about making an absolute value circuit with LM324AN op-amp ICs, 1N4004 diodes and resistors aplenty.





No comments:

Post a Comment

arduino - Can I use TI's cc2541 BLE as micro controller to perform operations/ processing instead of ATmega328P AU to save cost?

I am using arduino pro mini (which contains Atmega328p AU ) along with cc2541(HM-10) to process and transfer data over BLE to smartphone. I...