Been playing and it's taken more than 30 mins, which forum software does not like.
Found that by playing with set colours, it's possible to invert in Express PCB. DESIGN- then on main menu- select VIEW, OPTIONS/COLOURS. Set tracks & corners ( top layer) to white, and ignore all others. Use colour show options to get rid of green and yellow , and you're left with an inverted design. Copy ( PRTSysRq) to Photodraw, paste, check size ( resize) and paste to the size of print medium you're using. It's possible in the print options to change this/size of printed sheet.
The board is for a 12v SMPSU /4W drive at +/- 1V from car supply. Betsy is being dragged into the 20th century
, but as she's got a chipped key system, and Swimbo loves to loose keys, I've decided to change over to a remote system for Swimbo to open doors/boot etc, BEFORE Swimbo locks us out by either loosing my key or locking keys in car. (AGAIN)
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Simple idea- car 12v nominal is sent to a 7805 to drop 12v nominal to 5v, then sent to a 5-12v mini SWPSU to get back to 12v . System is set to operate ONLY when ignition is off, as power is sensed by a relay and supply to
remote unit shut off when ignition is on. In truth- I've had a prototype of this running on a bit of vero board, but I've noticed a lot of green on the board, and as I've decided to put it on PCB, with some form of moisture protection, I decided to put in the only on when ignition off option, to protect against any in motion voltage spikes.