🚀 go-pugleaf

In article <1jhvkuINNb8d@flop.ENGR.ORST.EDU>, slezal@gyro.ECE.ORST.EDU (Lee Slezak) writes...

>I am looking for some plans to build a charger for sub-C size nicad batteries.

I have a serious Ni-Cad fetish.  I have them in everything I own, flashlights,
music equipment, etc.  I have a number of simple chargers based on the LM317
voltage regulator, used as a constant-current source.  All you need for a 
charger is a DC supply that puts out 3-4 volts more than the battery pack
voltage. Feed the DC through the LM317 to limit the current to 10% of the
cell capacity (e.g. 100 mA. charging current for 1 Amp capacity cells).  The
LM317 current limit is programmed by a resistor between the output and Vadj
pins.   See the National Linear book for the circuit and the formula to 
calculate the resistor (Iout = 1.2/R, I Think).  You may need a heat sink if
the regulator has to dissipate more than a watt or two.

The constant-current charger will properly charge battery packs of varying cell
numbers.  Fourteen hours at .1C will give a full charge.