One of the projects we did many years ago was an automatic block=20 heater cord unplugger. The female end of the extension cord was=20 plugged in as normal. When the engine was started, a screw mechanism=20 retracted the blades of the male plug and caused the female end of=20 the extension cord to simply drop away. Really cool and worked quite=20 well - but I never heard anything about it after we had built the=20 proof-of-concept prototype. As I recall, the screw mechanism was driven by the motor assembly=20 from a really cheap Chinese-made hand drill. The engine running=20 detect was done by wrapping a wire around one of the spark plug=20 wires. Pretty simple stuff, really. But the customer was ecstatic=20 when he got it. dwayne At 01:51 AM 11/22/2014, Justin Richards wrote: >Thanks rich, > >I can imagine from your explaination that there's many stories of people >driving of without unplugging first. > >And wrt the plugs I take it from the description it is what I know as a >welch or core plug that are used to plug the holes that the moulding sand >is poured out of. > >Cheers Justin > > > There is another type that is inserted in to the engine block in > > place of what we Americans call a freeze plug. I believe you folks call > > it a soft plug. Again you plug it in at night and it will keep the > > coolant at about freezing in 30 or 40 degree f below zero temperatures. > > >-- >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .