If you can understand my description, this circuit works fine.

                      +12V                                   +5V
                         |      k                                    |
                  IN4004                                     4K7
                         |      a                                     |
                    100R                                         *----out
Points               |                                             |
--------10K-----*-------*---10K----*------BC338
                         |          |                  |                |
                    100R     10n            10K            |
                 k     |           |                  |            Gnd
                  IN4004     |              Gnd
                 a     |         Gnd
                    Gnd



Tony

For the beginner....
PicNPoke Multimedia 16F84 Simulator Assembler, and Tutorial.
Now with PicNPlay circuit simulator.
Plus animated Address Mode Tutor.

http://www.dontronics.com/picnpoke.html