🚀 go-pugleaf

On Sun, 06 Oct 2002 23:34:09 GMT, ehsjr@bellatlantic.net wrote:
>
>Johnny,
>
>The 317 in this configuration serves no useful purpose.
>Limiting current to the 9 strings in parallel does not
>limit the current to individual strings. One string can
>"hog" as much as it is capable of, up to the limit established
>by the LM317. You're looking to keep the current through
>each LED to 25 ma - your circuit won't do that.

Here is *yet* another circuit that provides better regulation for all
series strings.  Each additional string will mirror the same current
that is passing though the first series string, although the regulator
only monitors the first string.


(+12~13.8V)----[ LM317T ]---------------------------- (output pin) 
                        [               ]   >                     <

                                |           <  36R             >  36R 
                                |           <                     > 
                                |           >                     <

                                -------------                       |

                                            |                       |

                                        [LED]               [LED]  
                                        [LED]               [LED] 
                                        [LED]               [LED] 
                                        [LED]               [LED] 
                                            |                       |
GND------------------------------------------------------------ 

regards,
Johnny.