This circuit is from an 80's technical newsletter. The circuit can use any general purpose transistor and its power supply can be changed with a resistive divider to use a single 9V battery.
Mouser Electronics is making available the new regulator type Buck FAN536600 from Fairchild for...
We found this circuit in an American 1980s documentation. Transistors may be general purpose...
This complete single cell protection system is suggested by Linear Technology in its 2005 manual....