Originally posted by radiant1
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3 Pole Kit from Rennaissance Meeting
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Originally posted by ricardo60 View PostWhy does the generator coil at the top have cores that stick up 1 inch above the coil bobbin whereas the cores in the 3 drive coils are flush?
Mark
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Quick note on the transistors I am toying with in regards to drive battery current consumed when tuned to about top speed with best spikes:
MPS8099 - 230mA
D44C1 - 370mA
MJL21194 - 260mA
So the D44C1 might be not as good since I have to 'pay' more to get more. Depends if the higher radient spikes add enough value to overcome consuming the extra 100mA... Only testing will tell!
Once I find a spare moment I plan on designing a cap dump system to make use of the gen coil. Fortunatly there is some great info here and on other sites that I need to read up on.
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Is there any use for a cap-dump circuit on the transient recovery side? One of my batteries(12v, 7aH, Pb, reads at 9v...) looks like an open circuit when I attempt to charge it, the neons go bonkers(blue and purple when they're supposed to be orange.. even lost a transistor the first time!)
I'm thinking the battery has been sitting in a discharged state for too long and seems to lack any capacitance so the transients are looking elsewhere to settle...
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Bedini strikes back
Well I took 2 steps forward, 1 back and then 2 more forward tonight. Thanks to some observations with my scope I found out that I had wired up my trigger circuit wrong and was not getting good firing on 2 transistors.
What I did was use 3 pots and 3 resistors, 1 each to control each transistor... well that split the current in a way that only 1 transistor was firing full on no matter how I adjusted things. Now I have 1 resistor and 1 pot controlling all 3 transistors and the results look much better
Originally posted by Shanjaq View PostIs there any use for a cap-dump circuit on the transient recovery side? One of my batteries(12v, 7aH, Pb, reads at 9v...) looks like an open circuit when I attempt to charge it, the neons go bonkers(blue and purple when they're supposed to be orange.. even lost a transistor the first time!)
I'm thinking the battery has been sitting in a discharged state for too long and seems to lack any capacitance so the transients are looking elsewhere to settle...
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I just received my three pole kit today. Though it was the classic kit it was pretty simple to put together. i am using a manual battery swapper inspired by Jeff (Bits) Wilson. I am working to bring my battery voltages back up. my two lowest voltage batteries are rising quite nicely.
i am using it as a single node tesla switch with the charging output from the kit pushing back in to the charging battery of the battery swapper. I have advanced the timing as far as the kit allows.
I'm hoping to either get one of Jeff's battery swappers or design one of my own.
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Please keep us updated as to your progress redeagle
I found some time amongst my holiday madness to redraw my schematic, hope it helps.
happy holidays allAttached Files
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Originally posted by kippered View PostPlease keep us updated as to your progress redeagle
I found some time amongst my holiday madness to redraw my schematic, hope it helps.
happy holidays all
Anyway i added a reed switch to the generator coil to pulse the coil an generate a spike. not as strong as the one coming from the drive coils but i figure it's a spike and being out of phase with the main spike may give me a benefit.
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transistor resistor
Originally posted by kippered View PostWell I took 2 steps forward, 1 back and then 2 more forward tonight. Thanks to some observations with my scope I found out that I had wired up my trigger circuit wrong and was not getting good firing on 2 transistors.
What I did was use 3 pots and 3 resistors, 1 each to control each transistor... well that split the current in a way that only 1 transistor was firing full on no matter how I adjusted things. Now I have 1 resistor and 1 pot controlling all 3 transistors and the results look much better
That is a strange result... unsure myself but it might be wise to try a different battery before getting to far ahead.
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Originally posted by minoly View Posthave you tried using one resistor (220 ohms 1watt for 12 volt) at the base of each transistor - then to one pot then to trigger coil? once tuned try replacing pot w/ resistor/s series and/or parallel.
Thanks for the input
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Something to watch out for: Transistor's Vceo and/or Vcb ratings MUST EXCEED the target potential on the charge reservoir, otherwise the transients will start to see the Transistor as a more favorable path at some point beyond the max rating. It simply can't provide sufficient pressure to push through the diode on the Collector, so it discharges internally... This only becomes a problem when you're trying to desulphate a battery using capacitor discharge method...
Also, just to speculate about DC Current Gain(Hfe) vs the Switching Speed(Ft): Transistors are Current-Controlled Devices, and your Trigger Winding is providing the Base Current as a mostly AC Waveform, which leads me to believe that it is the DC Current Gain which will give you the sharpest Rise-And-Fall Times on the switched output. An average Switching Rate (Ft) in the MHz range should be more than adequate to render such a curve which is ultimately determined by the induced current in the Trigger Winding.
Hope this helps, ideas?Last edited by Shanjaq; 12-21-2010, 01:49 AM.
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Originally posted by Shanjaq View PostSomething to watch out for: Transistor's Vceo and/or Vcb ratings MUST EXCEED the target potential on the charge reservoir, otherwise the transients will start to see the Transistor as a more favorable path at some point beyond the max rating. It simply can't provide sufficient pressure to push through the diode on the Collector, so it discharges internally... This only becomes a problem when you're trying to desulphate a battery using capacitor discharge method...
Also, just to speculate about DC Current Gain(Hfe) vs the Switching Speed(Ft): Transistors are Current-Controlled Devices, and your Trigger Winding is providing the Base Current as a mostly AC Waveform, which leads me to believe that it is the DC Current Gain which will give you the sharpest Rise-And-Fall Times on the switched output. An average Switching Rate (Ft) in the MHz range should be more than adequate to render such a curve which is ultimately determined by the induced current in the Trigger Winding.
Hope this helps, ideas?
I read the other SSG thread about using a bipolar switch to help with switching off. I need to get an understanding of how the pnp helps switch the npn off faster. More to read up on I guess
I also played with the kit for a few minutes tonight (much to my wife's dismay) and found out that my trigger circuit does not work right still and it drives one transistor harder than the other two.
I will test but I think it proves minoly right that you need a standard base resistor that is the same for all 3 transistors so that the current divides evenly amongst the 3 transistors otherwise it heads for the transistor with the least internal resistance and drives it harder.
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Just a quick post of the driver circuit build in case anyone wants ideas to tighten things down. All speaker wire and direct connections bounded with copper embossing foil and glued to a sheet of acrylic with terminal blocks for convenienceAttached Files
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I have been working on my unit for several weeks now and am using two brand new PS1250 5 AH batteries. Very roughly I have a COP of .3 and I see no radiant spikes on the collectors of the 3 transistors. Therefore I am simply charging the charge battery from the run battery in a "traditional" fashion at roughly 30% efficiency.
Currently it is running at 5000 RPM at 160mA of run battery current. I am looking at the base resistor voltage with 1 channel of my 60MHZ Tektronix 2213 scope and the collector of a transistor on channel 2. The trigger signal goes to a 1K trim pot and then to the 3, 220 ohm resistors that go to the individual bases of the 3 transistors. The signals look very similar to others posted on the Yahoo group but without the radiant spikes.
I can only get 5000 RPM if the trigger coil is pushed or pulled to the most extreme right or left position. If at bottom dead center max RPMs are about 2270.
Tuning is not sharp at all (in any trigger coil position from bottom dead center to either extreme) but there is a broad range of pot tuning that does minimize run current and maximize RPMs.
Any ideas on what to do? Like change to different transistors (currently using the supplied 8099s) and/or pushing the core rods closer to the wheel and/or lowering the base resistor values (currently 200 ohms each).
Richard
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