3 ms·
My usual design is to monitor AC powerline with opto-coupler and then enter the brownout procedure in MCU when the power loss is detected. The remaining energy
by garganzol 7y ago
My usual design is to monitor AC powerline with opto-coupler and then enter the brownout procedure in MCU when the power loss is detected. The remaining energy stored in AC/DC converter capacitors are then used for a graceful shutdown purposes.
The usual brownout procedure actions are: a) flush the current state to MCU flash memory (EEPROM) so that the work can be automatically resumed; b) wait for a power-on condition.
In this way, the device is able to significantly reduce flash memory wearing. It turns to be a significant winning factor in cheaper MCUs, as they only allow about 100,000 EEPROM write cycles max.
And it comes for cheap, as the only thing you need is an opto-coupler plus a bit of software wizardry.