I'm using ACS712 hall effect current sensor to detect presence of current in the power line of a remote device. I don't need exact current value but rather just want to know if it's above certain threshold (0.2A in my case). 50Hz 0.2A AC current will result in 50Hz 37mV AC voltage signal with +2.5V offset. I'm planning to feed rectified and smoothed output to a comparator so it can trigger microcontroller when it's above threshold. I've tried to copy schematic from the datasheet of the IC but it doesn't seem to do what I want in the simulator. No matter what I do with voltage source, output at the capaciter upper leg seems to stay at 2.5V. What am I doing wrong here?
Allright, I've played with schematic a little bit and looks much more promising now! It still gives my only 10mV of detection margin at the threshold but it's better than nothing!