just to make sure no one has a misunderstanding, heres what i meant.
The alternator can self ignite itself at high rpm's. The cell also holds a charge, this charge is greater than what 2 AA batterys in series can offer a coil.
so if you pulse a coil with 2 AA batteries you dont hardly get much, if you do it with a cell, there is something in the cell that opens a can of worms on any coil, try it.
Before the alternator can self ignite, it has to be spinning. during freespin nothing connected, the stator outputs a very small voltage, im not sure it will even show up on the voltage meter.
now you take the rotor leads, you connect both of them to the stator and you hold them, nothing will happen. you keep holding them. the stator will appear to start resonating with the rotor. there will come a point to where you will have to start regulating, if you fail to regulate you will blow your diodes. The stator only works connected to the rotor in one direction.
now that you got that out of the way, you hook the cell to the stator, remember the cell holds a charge, so you connect it to the stator with the same polarity, this also helps the alternator to self ignite faster.
when you get the alternator self ignited, the power comming from the stator going into the rotor has to be regulated, if not you will be going at full blast and this will blow your diodes, not to mention your driver motor couldn't handle the torq.
to regulate you put a fet between the rotor and stator, you regulate voltage and amperage coming from the stator going into the rotor. The way the regulation works is the fet becomes a resistor that pulses. fets dont like to be a resistor, the want to be all the way on, or all the way off. when you run them inbetween they get hot and smoke.
the FQA30N40 is a good fet to be used as a pulsing resistor, if it did not resist current you could not regulate.
the problems i had with the new fets in the above post is they did not resist properly, they would not self ignite the alternator properly, when these fets reached a point to where it would self ignite the alternator, they self ignited it at full blast now allowing you to regulate down. when you tried to regulate down it would cut off.
to solve this problem with those types of resistors that has funny resistance when in use, i had to add resistance to them, i did this by placing a coil between the fet and rotor, this gave it more resistance, i could then regulate smoothly, by this time i had already ruined all my fets for past trouble shooting.
also the pulsing fet, known to me as a pulsing resistor causes a sort of harmonics to the fuel cell. the reason for the fet is you have to vary the amplitude of the voltages going into the cell, this amplitude is related to the rpm's at which the alternator is spinning at. when you regulate this way you get harmonics.
other problems i came across is much like the dave lawton circuit. you have a 220 ohm resistor comming from the gate of the timer going to the gate of the fet, and you have a 820 ohm resistor comming from ground going to the gate of the fet. the 820 ohm resistor shuts the fet off. however the fets i had refused to work with the 820 ohm resistor in place. the other fet refused to work with any resistor in place.
in most fets datasheets it will tell you that the fet gate should be around 5 volts 250ua, the timer is plenty good enough for the fet without having to use external drivers to gate the fet.
you dont want the fet to be all the way off, the fet is not just there to allow pulses to go threw, the fets job and main function is to become a pulsing resistor. the FQA30N40 used both resistors.
so it is problematic for me to bring you guy's a schematic because the schematic has to be build around the fet you're using. however i did get the new fet to work, it still got hot, its a very poor fet to use.
maybe stevie will post the fet he is using, im not sure how his fet holds up under attack. But atleast you see what you need, the fet does not send pulses to the alternator, it gets voltages from the alternator, and it lets it LOOP around acting as a switching and pulsing resistor. i will throw together a very simple circuit soon
