Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.csd.uwm.edu!bionet!apple!oliveb!amdahl!pacbell!ptsfa!dmt
From: dmt@PacBell.COM (Dave Turner)
Newsgroups: sci.electronics
Subject: Re: NiCd battery charger
Message-ID: <4935@ptsfa.PacBell.COM>
Date: 21 Aug 89 20:47:18 GMT
References: <349@uc.msc.umn.edu>
Reply-To: dmt@PacBell.COM (Dave Turner)
Organization: Pacific * Bell, San Ramon, CA
Lines: 28

In article <349@uc.msc.umn.edu> jeff@uf.UUCP (Jeff Turner) writes:
>I am interested in building a NiCd battery "Delta Peak (rapid) Charger."
>Apparently this type of charger detects a peak in something (voltage?) when the
>battery is fully charged and automatically shuts off to avoid over charging.
>
>I am interested in any information, including pointers to papers or articles
>on the subject.

Wireless World Nov 1983 has a construction article on such a fast NiCd charger.

It alternately charges and discharges the cells until the peak charge and
discharge voltages begin to diverge; it then switches to standby.

The article claims that it is "capable of charging all common cell types in
an hour or so, with a single switch to accommodate batteries of different
sizes." The charging is not affected by the number of cells in series.

I have not made one of these but except for a few parts substitutions
(BC transistors, a diode or two and a toroidal ferrite core) it looks
fairly routine.

For only &7 (7 pounds) you can order a ready-drilled glass fibre printed
circuit board.

PS Are we related?

-- 
Dave Turner	415/542-1299	{att,bellcore,sun,ames,decwrl}!pacbell!dmt