Tim Kerby wrote:
>
> Hi
> How about an intelligent battery charger someone.  To be able to charge
> NiCad, Lead Acid (sealed gel type), NiMH and others using bulk, float and
> trickle charging at various voltages to get the best performance all in one
> unit would be great.  PIC control with an LCD and mini keypad anyone?

I just did one without a micro. I used junkbox components only.
Basically it is a constant current (preset .1C - 1C) charger that
starts to pulse as soon as a predetermined level is reached. A LED
tells you when it is charged. The pulse width decreases when the
voltage still goes up. If you throw the switch, it discharges through
a 22E 5W resistor down to another preset level where a LED will warn
you.
Total component count? One darlington transistor, a dual opamp, two LEDs
8 resistors, a diode and a spdt switch.

--
Friendly Regards

Tjaart van der Walt
mailto:tjaart@wasp.co.za
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