At 01:20 PM 12/10/2004 -0500, you wrote:
>Still working on charging batteries here.  It seems the more I learn, the 
>more I realize I need to know!
>
>I was looking at the PIC charger mentioned at
>
>http://www.angelfire.com/electronic/hayles/charge1.html
>
>It uses a transistor to control a LM317 configured to deliver 1.25A (~=C).  
>However the text of the page indicates that the circuit can deliver C/5, 
>C, and C/25.  I really don't understand how the C/5 and C/25 can be used.
>
>The circuit itself is at 
>http://www.angelfire.com/electronic/hayles/charge1fig3.html

He's using PWM as shown in Fig.2, so switching the transistor at 50% duty
cycle gives C/2=.63A, although I didn't realise you'd still observe the
'full charge' voltage drop with this method. He also does'nt state the base
frequency he's using. Guess he wants you to buy the chip!


Regards
Roland Jollivet

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