The wheel specs are 18 x 2x1x1/2 double stacked north out.
It's not the trigger potentiometer or coil where the heat has manifested.
I have put a resistor across the capacitor bank on the secondary output to simulate a load and drain off excess voltage.
That resistor is toasty even at 600ohms.
There is no battery on the secondary yet.
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Originally posted by Deuis View PostThe SG doesnt run without power assist as yet.
I haven't loosened the bearings or fixed the aerodynamics and the wheel weighs about 5kg.
There are variances in motor load during this test indicating that the SG is putting out some torque.
Heres some more data.
I tried to keep the wheel at 200rpms as best I could then varied the secondary load.
The resistor in the picture is 600ohms, 50W.
Thats a 73degree differential, Im assuming that is roughly 50W of heat output.
Ive been looking for some heat specs for this resistor but cant find any.
Ohms law tells me 73 volts across 600ohms = 8.88W
I dont think 8.8W is pushing a 50W resistor 73degrees higher than ambient.
[ATTACH=CONFIG]6954[/ATTACH]
[ATTACH=CONFIG]6952[/ATTACH]
[ATTACH=CONFIG]6953[/ATTACH]
I forgot to mention the obvious.
Primary at 12.7V @ 600ohm = .269W
"-18 magnet wheel.
-North out double stacked 2" x 1" x 1/2" ceramic magnets and the large north out NEO's."
?
if so you might be generating too much in your trigger winding which would be the reason there is so much heat... in addition some of that gauss is ending up in your battery rather than just radiant.
Kind regards.
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The SG doesnt run without power assist as yet.
I haven't loosened the bearings or fixed the aerodynamics and the wheel weighs about 5kg.
There are variances in motor load during this test indicating that the SG is putting out some torque.
Heres some more data.
I tried to keep the wheel at 200rpms as best I could then varied the secondary load.
The resistor in the picture is 600ohms, 50W.
Thats a 73degree differential, Im assuming that is roughly 50W of heat output.
Ive been looking for some heat specs for this resistor but cant find any.
Ohms law tells me 73 volts across 600ohms = 8.88W
I dont think 8.8W is pushing a 50W resistor 73degrees higher than ambient.
I forgot to mention the obvious.
Primary at 12.7V @ 600ohm = .269WLast edited by Deuis; 06-20-2018, 03:59 AM.
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Does the resistor run cool without the power assist? i.e. just the SG pushing the wheel around?
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Me too,
I swapped the 200ohm out for a 600ohm and same thing.
Voltage went up by about 40% and sat on about 80 degrees.
I hooked a 15W x 240V globe across it for a decent glow.
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Interesting experiment as above.
Typically the 12.7V power source could only ever supply .811W to a 199 ohm resistor.
After triggering, the stable voltage at the capacitor varies between 30-60V as results show.
The resistor was certainly too hot to touch (>50C) during the experiment probably indicating that a load between 7 and 18W is in the ball park. (12degrees Celsius ambient)
next experiment will involve varying the trigger resistance and I should be able to chart the most efficient combination of air gap and trigger resistance.
I'll use a 6mm air gap as it seems like a common number (1/4") which still aligns with my data.
Infra-red thermometer told me resistor was at 125 degrees celsius through last round of testing.
Resistors are typically rated to dissipate at a 70degree threshold indicating that it is dissipating >50W of power.
Can't see it in the meter's as yet....
Using calc's for 50W @ 199ohms = 100V @ .5A
Using backward calculations doesn't enthuse me but the heat is real??
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Some Data on the standard SG with variable air gap.
I started at the closest setting of 3mm then walked it out 1mm at a time until the lowest speed did not trigger.
With motor assist i'm not relying on tuning to turn the rotor, it is a seperate isolated function of the circuit.
SG power usage is not calculated in this data.
The 50W resistor was running about 70degrees celsius.
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Please dont clog up this post.
This is a standard SG setup with an assisted motor.
8 filar coil, 1 trigger, 7 Power.
You can see the Potentiometer.
Surely you must know this by now.
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Originally posted by Deuis View PostI have now hooked up the SG circuit to the 8 filar 18ga coil.
Under power assist I can dial down to a speed where the transistors are only just firing and maintain that speed.
I've had it running on 5 pulses per pass charging a large capacitor bank up over 300V.
Primary 12V running at 1A on an analogue meter.
Air gap 16mm, ive been running it in and out but nothing substantial yet.
I can now ignore the motoring effect and focus on the best charging rate.
[ATTACH=CONFIG]6941[/ATTACH]
I see that your strands are not sufficiently
twisted... you said its an 8-filar coil is that including the trigger??
Best Regards,
Faraday88.
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SG assissted
I have now hooked up the SG circuit to the 8 filar 18ga coil.
Under power assist I can dial down to a speed where the transistors are only just firing and maintain that speed.
I've had it running on 5 pulses per pass charging a large capacitor bank up over 300V.
Primary 12V running at 1A on an analogue meter.
Air gap 16mm, ive been running it in and out but nothing substantial yet.
I can now ignore the motoring effect and focus on the best charging rate.
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Originally posted by Bradley Malone View PostFaraday. Yes the advanced book is great. But I always keep an open mind about the fact that anybody can be wrong. Even bedini could have missed something that could have added to his design to do something different or more output etc... So when it comes to testing why not try anything and just see. Experience is the best teacher.
I actually do a great deal of testing but struggle with extreme ADHD so writing up information into a readable format that can help someone is just not a strong suit. I am however working on a microcontroller circuit for switching motors generators or coil shorting, really anything
precisely with mechanical relays because of the benefits from a solid make/ break connection instead if trying to use a thousand different transistors to find the best one. The controller is being set up to measure rpm while sensing exact position of rotor magnets with many variables so I can connect or disconnect anything at any point I want. When I get it finished debuged and tested I was planning on offering the code on here or even a complete unit with relay module so people can just get it hook it up and experiment with any timing scenario they would want.
I'm glad to here about the mind set and the approach you have!!.. yes open mindedness is indeed the way to go ahead!! and as you rightly said : 'Experience is the best teacher' I call it as the first handed experimenting..and ofcourse we all can be wrong..because Science can be interprtead in many ways...its like we speak different langauges but in the end mean the same thing!
JB nonetheless was always candid in what he stated..we woe him a lot, he was a novel experimenter i must say!!
Best Regards,
Faraday88.
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Faraday. Yes the advanced book is great. But I always keep an open mind about the fact that anybody can be wrong. Even bedini could have missed something that could have added to his design to do something different or more output etc... So when it comes to testing why not try anything and just see. Experience is the best teacher.
I actually do a great deal of testing but struggle with extreme ADHD so writing up information into a readable format that can help someone is just not a strong suit. I am however working on a microcontroller circuit for switching motors generators or coil shorting, really anything
precisely with mechanical relays because of the benefits from a solid make/ break connection instead if trying to use a thousand different transistors to find the best one. The controller is being set up to measure rpm while sensing exact position of rotor magnets with many variables so I can connect or disconnect anything at any point I want. When I get it finished debuged and tested I was planning on offering the code on here or even a complete unit with relay module so people can just get it hook it up and experiment with any timing scenario they would want.Last edited by Bradley Malone; 03-06-2018, 10:50 AM.
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