HeadSmess
Well-Known Member
- Local time
- 9:32 AM
- Joined
- May 17, 2010
- Messages
- 3,048
i myself, havent found any engine that uses the HT style magneto or cdi, that is... only two wires, one of which is earth, so technically one wire.
it is a strange little device that seems to work fairly well. with plenty of room for improvement, as this and other threads may suggest.
basically, coil charges a hi voltage cap on the positive cycle. this charge is trapped via diodes and thyristor. the thyristor is switched on as the negative cycle reaches the critical voltage, discharging capacitor through primary of ignition coil, generating spark on secondary.
try neo magnets, of course. remember that they lose magnetism at very low temperatures. less than 100 degrees c. holding them in against centrifugal force, and of course, lining up the edge to create the correct tigger and charge pulses at the correct times.
regards generating power though, they seemingly are ideal. more magnetic lines of flux cut by a conductor, the more power created. easy. neo magnets are super strong
because of the way the cdi works it would affect advance curves. separate trigger solves that.
also you start getting into saturation, permeability and hysteresis loops because of the extra magnetic power. iron of a given alloy can only carry so many lines of magnetic flux,so at a certain point, theres no gain in using more powerful magnets...
maybe i just overcomplicate things and im talking rubbish again
the cdi circuit i think i posted in this thread, has a few flaws. it works, but is flawed. minor changes, and its a reliable unit. it will produce a spark with any type of transformer with a suitable turns ratio even as shown.
i got all setup, designed a nice PCB, ordered enough caps and diodes to make 50...nothings arrived.twice. how olds this thread now? thats how long ago as always, another 90% finished project. what the #$% do i do with 50 PCB's? got the resin, mica goop for extra insulation, sockets and plugs, and...no components.
i think i smashed a few mirrors cus thats how lifes treating me
nothing strange about your questions at all
it is a strange little device that seems to work fairly well. with plenty of room for improvement, as this and other threads may suggest.
basically, coil charges a hi voltage cap on the positive cycle. this charge is trapped via diodes and thyristor. the thyristor is switched on as the negative cycle reaches the critical voltage, discharging capacitor through primary of ignition coil, generating spark on secondary.
try neo magnets, of course. remember that they lose magnetism at very low temperatures. less than 100 degrees c. holding them in against centrifugal force, and of course, lining up the edge to create the correct tigger and charge pulses at the correct times.
regards generating power though, they seemingly are ideal. more magnetic lines of flux cut by a conductor, the more power created. easy. neo magnets are super strong
because of the way the cdi works it would affect advance curves. separate trigger solves that.
also you start getting into saturation, permeability and hysteresis loops because of the extra magnetic power. iron of a given alloy can only carry so many lines of magnetic flux,so at a certain point, theres no gain in using more powerful magnets...
maybe i just overcomplicate things and im talking rubbish again
the cdi circuit i think i posted in this thread, has a few flaws. it works, but is flawed. minor changes, and its a reliable unit. it will produce a spark with any type of transformer with a suitable turns ratio even as shown.
i got all setup, designed a nice PCB, ordered enough caps and diodes to make 50...nothings arrived.twice. how olds this thread now? thats how long ago
as always, another 90% finished project. what the #$% do i do with 50 PCB's? got the resin, mica goop for extra insulation, sockets and plugs, and...no components. i think i smashed a few mirrors cus thats how lifes treating me
nothing strange about your questions at all
