I'm using the 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 (0.2 A in my case). 50 Hz 0.2 A AC current will result in 50 Hz 37 mV AC voltage signal with +2.5 V offset. I'm planning to feed rectified and smoothed output to a comparator so it can trigger a microcontroller when it's above threshold.
I've tried to copy the 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 the voltage source, output at the capacitor upper leg seems to stay at 2.5 V. What am I doing wrong here?
I've played with the schematic a little bit and looks much more promising now! It still gives me only 10 mV of detection margin at the threshold but it's better than nothing!