http://www.uoguelph.ca/~antoon/circ/batmon12.htm
http://www.musicfromouterspace.com/analogsynth/ninevoltsupply.html
active temperature sensor in the rechargeable battery pack does not drain the battery, and it needs only one terminal for its power-supply input and temperature output, output suitable to be connected to a microcontroller
http://www.edn.com/archives/1996/080196/16di3.htm
http://www.uoguelph.ca/~antoon/circ/battest.html
this dc/dc converter allows you to replace a five- or six-unit string of NiCd coin cells with one cell
http://www.edn.com/archives/1997/020397/03DI_04.htm
detects 295-nm UV radiation, which is dangerous to eyes and skin
http://www.edn.com/archives/1994/120894/25di1.htm
circuit monitors two lithium-ion batteries and protects both of them against overcharging, overdischarging, and undervoltage
http://www.edn.com/archives/1997/060597/12di_05.htm
http://www.uoguelph.ca/~antoon/circ/ps3010/ps3010a.html
http://www.uoguelph.ca/~antoon/circ/ps3010/ps3010b.html
http://www.uoguelph.ca/~antoon/circ/ps3010/ps3010c.html