Hallo!

Sollte ab 0V funktionieren...aber nicht geprüft. Bild  

MfG
Code:
                                          1N400x
                             +--------------|<------------+
                             |                            |
            BG               |         1k/4W  I           |
          .----.          Ui | .-----.  ___ -->.-----.    |
          |+--+----------+---+-| LM  |-|___|-+-| LM  |----+--+---+-->+
          ||  ||+        |   | | 317 |   A   | | 317 |    |  |   |
          |-  -|         |   | '-----'   |   | '-----'    |  |   |
          |^  ^|         |   |    |      |   |    |  ___  |  |   |
     Tr  ~||  ||         |+  |    +------+---+    +-|___|-+  |   |+
 <---. ,------+|        === ---        Strom      |  220    --- ===
230V )|(  ||  ||        /-\ ---                  .-.        --- /-\  Uo
50Hz )|(  ||  ||         |   | µ1                | |<--+  µ1 |   |
 <---' '---+  ||         |   |          Spannung | |   |     |   |
         ~||  ||         |   |                   '-'2k2|     |   |
          |-  -|         |   |                    |    |     |   |
          |^  ^|         |   |                    |    |     |   |
          ||  ||-        |   |                    |    |     |   |
          |+--+--+-|<-|<-+---+----------------+---|----|-----+---+-->-
          '----' |2x1N400x                    |+  |    |
                 |                           ===  |    |
                 |                           /-\  |    |
                 |                            |   |    |
                 +----------------------------+---+----+ ~ -1,2V
                                                         gegen - Uo


                   Ui min = 19,25 V ( Uo max +  min. 7,25 V ) 

                   Uo min = ~ 0 V       Uo max = ~ 12V 

                    I min = ~ 1 mA 

                       BG = Brückengleichrichter