Thanks, yes that's the principle I'm looking for RP On 21/01/06, Peter wrote: > > On Fri, 20 Jan 2006, Danny Sauer wrote: > > > I'd imagine there are examples somewhere of how to use a hall-effect > > switch to control power to an inductor through a transistor. :) Maybe > > look around the DIY-EFI - http://www.diy-efi.org/ - and megasquirt - > > http://www.megasquirt.info/ - sites. > > Most low cost magneto style electronic ignitions do not use a hall > switch they use dI/dt sign change to cut the current circuit at the > right moment. This can be achieved with something as simple as one > transistor and two coils but usually there is more to it. Take a look at > the simple circuits required to make a battery powered 'pendulum' toy. > The ignition electronics work almost the same. Here is a circuit that > may provide some ideas: > > http://www.geocities.com/~uwezi/electronics/projects/pendulum.html > > To use as a magneto replace the battery with the primary of an ignition > coil and use a hefty magnet. The polarity of L1 may have to be reversed > and something better used for Q (MOSFET should work). > > Peter > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist