This is basically the opposite of the common Constant Current circuit, built from one BJT, and a Zener, LED(s), or another Transistor. This circuit stays nonconducting until the Input Voltage reaches 7 Volt, (depending on the chosen bent curve element, and "switches" to conducting above that value. I designed it to prevent deep discharge of a 12V, 4.4Ah NiMH cell pack, I use to power a portable Class D Audio Boom Box. Let's see, if that works out in meatspace, or if I'll need a bunch of comparators and Mosfet driver chips soon.
