Path: utzoo!attcan!uunet!zephyr.ens.tek.com!tekig5!brianr
From: brianr@tekig5.PEN.TEK.COM (Brian Rhodefer)
Newsgroups: sci.electronics
Subject: Re: Photovoltaic charger for NiCads
Message-ID: <5071@tekig5.PEN.TEK.COM>
Date: 20 Nov 89 23:38:03 GMT
References: <1749@lafcol.UUCP> <7200043@silver> <31730@buckaroo.mips.COM>
Reply-To: brianr@tekig5.PEN.TEK.COM (Brian Rhodefer)
Organization: Tektronix, Inc., Beaverton,  OR.
Lines: 17

In article <31730@buckaroo.mips.COM> vaso@mips.COM (Vaso Bovan) writes:
>In article <7200043@silver> commgrp@silver.bacs.indiana.edu writes:
>>
>>Remember to put a silicon diode in series to block ... reverse leakage,
>>and remember that about 0.6 volt is lost in the diode's forward conduction.

>
>Germanium diodes (0.3V) and some schottky diodes are more efficient than
>silicon diodes in low voltage charging circuits.

Power MOSFETs are available with on-resistances down into the tens of
milliohms nowadays.  One of these, with suitable CMOS "smarts" to make
it imitate a rectifier, would cut the forward losses below even those
obtainable with germanium diodes.


Brian Rhodefer