The things I was saying about BR and diodes also apply to bipolar junction transistors. That is why microwave transistors have lower breakdown voltages--their junction capacitance must be kept very low to permit them to have gain over a higher & wider frequency bandwidth often into the several gigaHertz range. MOSFETS also have gate capacitance that must be considered for higher frequency applications for the impedance of the driving circuits used.
The idea of ringing the resonance (or harmonic thereof) of a coil would work nicely if that coil also had some drive applied to it also. The current needed to drive a coil & capacitance in resonance would be minimal, but as soon as you get away from resonance, the current draw would increase dramatically.
The picture should show a negative going dip below zero volts DC that recovers back to zero volts after this stray junction capacitance discharges. This junction capacitance can amount to quite a number of picoFarads, that, at high frequency, can cause complete pass through of the signal that is being attempted to be rectified by the diode in use. This goes especially for bridge rectifiers not meant for other than 400 Hz and lower.
The more voltage that the diode blocks, the larger the E-field gets inside the PN junction region--until the diode breaks down due to too high a peak inverse voltage (PIV)--breakdown voltage.
To get higher frequency diode operation, the semiconductor manufacturers use methods to decrease this charge capacitance so that reverse recovery time to discharge this junction capacitance is much smaller. Google ("reverse recovery time"), then do the same search for images--you'll get the picture.
A diode's recovery time is from the capacitance of the electric field at the PN semiconductor junction. When you take the existing PN junction electric field and reinforce it, the diode is blocking current flow, i.e., it is in reverse or blocking mode. When the PN junction electric field is being depleted / opposed by the incoming voltage, the diode fights to re-establish its normal PN junction field whilst you are busy depleting it, thereby, the diode is in forward conductance mode.
I was browsing overunity com and saw one of your posts about Bedini motors that linked here. I watched a few of your videos. What struck me was the use of reed switches and bridge rectifiers. You know, of course, that the frequency response of these is on the slow / low frequency part of the spectrum? The only bonus with a BR is usually it has higher PIV than fast or ultra-fast recovery diodes or Schottky diodes. Most wall socket frequency applications are 50 / 60 Hz when using a common BR type.
Lenz's law produces a braking action when a loaded coil is in proximity to the moving permanent magnets because the induced field opposes / repels each moving permanent magnet. The stronger the induced magnetic field gets with the same amount of resistive or capacitive loading of the coil, the more the braking action. If you used ferrite cores to intensify the field strength picked up by the big loaded coil, then the braking action would be huge.
It means that the capacitor and coil want to ring at a particular freq, So when the rotor gets to a speed that the rotor magnets ar producing the same freq that the coil/cap want to ring, they are in sync and we get more voltage from the coil also
Thanks. I was having battery charge issues last night, and I felt stressed when I made the vid. Could have been better. Will be doing more on this. ;]
Really, really interesting Mag :) Do you think the magnets stop jumping because without the caps there is less parasitic capacitance on the gen coil ? Thanks for sharing.
The magnet jumping around the big coil shows that there is a lot of activity when it is near or at resonance. If you have ever made a lead crystal wine glass ring with a wet finger dragged across the rim, it will sing. And if you have water in the glass, you can see the vibrations in the water, like the magnet dancing around. ;]
It was basically to show that the coil is very active at resonance and not otherwise. ;]
Can't believe I missed this video. Very nice presentation, Thanks.
V
blackchisel97 1 month ago
The things I was saying about BR and diodes also apply to bipolar junction transistors. That is why microwave transistors have lower breakdown voltages--their junction capacitance must be kept very low to permit them to have gain over a higher & wider frequency bandwidth often into the several gigaHertz range. MOSFETS also have gate capacitance that must be considered for higher frequency applications for the impedance of the driving circuits used.
oldspammer 5 months ago
The idea of ringing the resonance (or harmonic thereof) of a coil would work nicely if that coil also had some drive applied to it also. The current needed to drive a coil & capacitance in resonance would be minimal, but as soon as you get away from resonance, the current draw would increase dramatically.
watch?v=kQdcwDCBoNY
oldspammer 5 months ago
The picture should show a negative going dip below zero volts DC that recovers back to zero volts after this stray junction capacitance discharges. This junction capacitance can amount to quite a number of picoFarads, that, at high frequency, can cause complete pass through of the signal that is being attempted to be rectified by the diode in use. This goes especially for bridge rectifiers not meant for other than 400 Hz and lower.
oldspammer 5 months ago
The more voltage that the diode blocks, the larger the E-field gets inside the PN junction region--until the diode breaks down due to too high a peak inverse voltage (PIV)--breakdown voltage.
To get higher frequency diode operation, the semiconductor manufacturers use methods to decrease this charge capacitance so that reverse recovery time to discharge this junction capacitance is much smaller. Google ("reverse recovery time"), then do the same search for images--you'll get the picture.
oldspammer 5 months ago
A diode's recovery time is from the capacitance of the electric field at the PN semiconductor junction. When you take the existing PN junction electric field and reinforce it, the diode is blocking current flow, i.e., it is in reverse or blocking mode. When the PN junction electric field is being depleted / opposed by the incoming voltage, the diode fights to re-establish its normal PN junction field whilst you are busy depleting it, thereby, the diode is in forward conductance mode.
oldspammer 5 months ago
I was browsing overunity com and saw one of your posts about Bedini motors that linked here. I watched a few of your videos. What struck me was the use of reed switches and bridge rectifiers. You know, of course, that the frequency response of these is on the slow / low frequency part of the spectrum? The only bonus with a BR is usually it has higher PIV than fast or ultra-fast recovery diodes or Schottky diodes. Most wall socket frequency applications are 50 / 60 Hz when using a common BR type.
oldspammer 5 months ago
Lenz's law produces a braking action when a loaded coil is in proximity to the moving permanent magnets because the induced field opposes / repels each moving permanent magnet. The stronger the induced magnetic field gets with the same amount of resistive or capacitive loading of the coil, the more the braking action. If you used ferrite cores to intensify the field strength picked up by the big loaded coil, then the braking action would be huge.
oldspammer 5 months ago
@Magluvin
Hi :)
Would be interesting to see what your ProbeScope shows while you're adjusting different caps and speed on rotor, maybe possible to get it on video?
Also, try variable input voltage so you might encounter different speeds as well while changing voltage on driwing coil.
Also, might be worth to try place hall sensor in other side of gen coil instead of rotot and see if that makes any sense to how motor runs..
Cheers!
T1000LTU 5 months ago
Very cool. That last few seconds showed a way to see resonance without an oscilloscope and on the fly - will use that way myself no doubt, thanks.
Looking at comments, that made a greater impression than how to GET the resonance hehe
slider2732 5 months ago
what is resonance lock? :))
nadinka007 5 months ago
@nadinka007
It means that the capacitor and coil want to ring at a particular freq, So when the rotor gets to a speed that the rotor magnets ar producing the same freq that the coil/cap want to ring, they are in sync and we get more voltage from the coil also
Mags
Magluvin 5 months ago
what is resonance lock? :))
nadinka007 5 months ago
great video
ken25taylor 5 months ago
@ken25taylor
Thanks. I was having battery charge issues last night, and I felt stressed when I made the vid. Could have been better. Will be doing more on this. ;]
Mags
Magluvin 5 months ago
Really, really interesting Mag :) Do you think the magnets stop jumping because without the caps there is less parasitic capacitance on the gen coil ? Thanks for sharing.
See you on the forums :)
deepcut66 5 months ago
@deepcut66
Hey Deep
The magnet jumping around the big coil shows that there is a lot of activity when it is near or at resonance. If you have ever made a lead crystal wine glass ring with a wet finger dragged across the rim, it will sing. And if you have water in the glass, you can see the vibrations in the water, like the magnet dancing around. ;]
It was basically to show that the coil is very active at resonance and not otherwise. ;]
Mags
Magluvin 5 months ago