Power-On Flasher & Low Battery Indicator for Active Basses & Guitars
The Indicator flashes a green light about once per second to remind you that your active electronics are on. When the battery voltage drops below 7 volts, the light turns solid red. Time to replace the battery before the tone starts to suffer! The Indicator draws a very tiny amount of current from the battery (just 30 microamps while flashing green), so it won’t drain it while monitoring it.
Watch the Demo
Make Your Own
It would make a nice first Surface Mount project for someone new to this, since only one of the parts (the dual comparator) is exclusively available in SMD packages. All other parts can be Through Hole.