psw Posted September 22, 2006 Author Report Share Posted September 22, 2006 EMIBucker? news: I built it, the coils work (one is 4ohm, the other 3.9) After my first trial, the results are inconclusive. There still seems to be a fizz in the background, and I think it's EMI fizz. I will do some more testing to see if there is a reduction compared to my single coil driver. Well done! Try the driver swung around 180 degrees or reverse the polarity of the magnet. It could be that the pole closer to the pickup is an opposite pole and is so attracted to the pickup, along with stray EMI. (remember the diagram of the interaction between humbucking pickups post a little way back)... It does seem to be a more efficient driver though, works my E string better and even with 14mm between the rails, there is not obvious note cancellation (again, more testing is required) - this adds more credence to the idea that wide driver cores will not be a problem. Well...the thin core is more of an idea than the thin driver is a theory Actually, I still think the thin core is a valid argument, but the rail style magnetics are a bit different. The two polarities close to one another focuses the field as it is attracted between the poles not in a ring around it...effectively making a tight field between the rails and so "thin" for all intensive purposes. 14mm seems quite wide though compared to what Tim produced, maybe your driver is even thinner. I'd be interested on how both of you arranged your magnet/s in this design. I could try modelling the idea in FEMM so we could see how the field compares to a single coil design. As for the "fizz", I only get this in the harmonic mode on super clear settings (I'll try and record it at some point) and am not entirely sure that it is EMI between the driver and the pickup. Perhaps it is EMI within the driver leads or circuit leaking back into the earth, or something of that ilk...it is still a little bit of a mystery. Speaking of Harmonic mode...I don't recall you mentioning this in previous posts...how has your drivers and circuit responded to a reversal of the signal? Also, you may want to try adjusting the output capacitor...you seem to be using a 220 uF, I have tried 470 uF down to 100 uF and found the 100 uF to be far superior in driving the high strings though you do get a typical and consistant octave feedback harmonic morph on lower strings/notes (up to about the A note, 2nd fret, g string). This alone would account for my better response of high strings if you haven't tried it yet. It's great news that you have successfully built it and it is driving so well though...even further proof of concept. That it could be more efficient is an interesting idea...I'm not sure I would have predicted that...I had wondered whether there may have been a trade off for efficiency and EMI reduction... Keep up the good work...this is moving pretty quickly lately...by the time I get around to playing with these concepts, the hard yards will have been done! http://www.projectguitar.com/uploads/emoticons/default_biggrin.png' alt=':D'> pete Link to comment Share on other sites More sharing options...
col Posted September 22, 2006 Report Share Posted September 22, 2006 Ok, done some more testing. I've checked each of my new coils as a single coil driver. They both work, but are both noisier than my original 8ohm driver ! I'm not sure if this is because they are only 4ohm, or (more likely) because i didn't wrap tape around the core before winding, maybe makes is a little more efficient, but possibly more noisy ? heh, most likely though is because at the moment for testing convenience, each side of the double coil has a lead almost twice as long as the one on my original driver. So, back to my results... I'm getting some fizz still, but the general level of noise from the dual core driver is much less than that from one side used as a single coil driver. More interestingly, with the new driver, and the lates incarnation of my circuit (a few changes since i posted the schematic) I can get a good even sustain from all strings at all frets (some slightly weaker, and some more likely to bloom to harmonics) with a current draw of around 20 - 22 mA Yep 20 - 22 !!!!!!!! - I hope this is a true reading, I think the battery on my meter is running a little low, however, I've had to turn the gain right down for the new driver, so it's probably about right. Batteries last a lot longer with lower drain. i.e. a 9v battery drained at 22mA will last more than twice as long as one drained at 44mA, and as it ramps up to say over 100mA all bets are off unless you are using some really hefty expensive battery technology If this is a true figure, we might get as long as 20 hours out of a single battery... thats running flat out. With no signal, and when playing hard, the drain drops to between 13mA and 18mA, so an actual battery life might even be as high as 30 - 35 hours playing time (depends how low the battery voltage can go before the circuit stops working) It may be that putting the circuit on a well layed out perfboard, and minimizing the lead length reduces the fizz to an acceptable level. Altenatively, I want to try isolating the driver circuit using a 1:1 transformer - this could be as small as about 12mm cubed - which may be acceptable... don't know if it works of course, so I'm going to keep a look out for a salvagable tranny to experiment with (don't want to spend about £8 + postage just on the off-chance) So its not the yippee i had hoped, but definately a big step forward. cheers Col Link to comment Share on other sites More sharing options...
onelastgoodbye Posted September 22, 2006 Report Share Posted September 22, 2006 I'd be interested on how both of you arranged your magnet/s in this design. I could try modelling the idea in FEMM so we could see how the field compares to a single coil design. Here you go: lousy big ass ceramic... Link to comment Share on other sites More sharing options...
col Posted September 22, 2006 Report Share Posted September 22, 2006 Try the driver swung around 180 degrees or reverse the polarity of the magnet. It could be that the pole closer to the pickup is an opposite pole and is so attracted to the pickup, along with stray EMI. (remember the diagram of the interaction between humbucking pickups post a little way back)... Heh, first thing i did was try all permutations - even tried parallel configs just out of interest (they sucked as expected) reversing the polarity of the magnet and/or switching the coils didn't _seem_ to make any noticable difference. (I could have made a mistake, so I will be trying all that stuff again (and again and again ) It does seem to be a more efficient driver though, works my E string better and even with 14mm between the rails, there is not obvious note cancellation (again, more testing is required) - this adds more credence to the idea that wide driver cores will not be a problem. Well...the thin core is more of an idea than the thin driver is a theory Actually, I still think the thin core is a valid argument, but the rail style magnetics are a bit different. The two polarities close to one another focuses the field as it is attracted between the poles not in a ring around it...effectively making a tight field between the rails and so "thin" for all intensive purposes. 14mm seems quite wide though compared to what Tim produced, maybe your driver is even thinner. I'd be interested on how both of you arranged your magnet/s in this design. I could try modelling the idea in FEMM so we could see how the field compares to a single coil design. Yep, my coils turned out just a little too fat for the 5mm wide magnet I wanted to use, so I ended up using a 13mm magnet from a humbucker pickup. Its in roughly the same config as onelastgoodbye one. The core is not laminated... Might be that using a narrower magnet and having the coils closer together improves the EMI cancellation ? (FWIW, I tried moving the driver around near the pickup, and got similar screaches and squeals to the ones a single coil produces.) Coil 3 mm thick core 56x10x2mm 1mm of core protruding above the (bobbinless) coil... (maybe this is another reason for the increased efficiency and noise when compared to my original driver - the original one had 2mm protruding at the top) Although I'm not sure how useful a FEMM model is to us becuase it can't incorporate the electromagnetic component of the feild ? As for the "fizz", I only get this in the harmonic mode on super clear settings (I'll try and record it at some point) and am not entirely sure that it is EMI between the driver and the pickup. Perhaps it is EMI within the driver leads or circuit leaking back into the earth, or something of that ilk...it is still a little bit of a mystery. Yep, I'm starting to think its related to shared earth. Thats why I want to get a small 1:1 isolation transformer to experiment with. Speaking of Harmonic mode...I don't recall you mentioning this in previous posts...how has your drivers and circuit responded to a reversal of the signal? Very well indeed - maybe a little to extreme, but thats easily controlable Also, you may want to try adjusting the output capacitor...you seem to be using a 220 uF, I have tried 470 uF down to 100 uF and found the 100 uF to be far superior in driving the high strings though you do get a typical and consistant octave feedback harmonic morph on lower strings/notes (up to about the A note, 2nd fret, g string). This alone would account for my better response of high strings if you haven't tried it yet. I tried that with the Fetzer/Ruby - all it really does is help balance the signal by filiering out the lower frequencies. My circuit balances the signal without needing to filter out the low stuff, and harmonic bloom can be encouraged in ways that don't kill the fundamental of the low E and A strings. It's great news that you have successfully built it and it is driving so well though...even further proof of concept. That it could be more efficient is an interesting idea...I'm not sure I would have predicted that...I had wondered whether there may have been a trade off for efficiency and EMI reduction... It's possibly more efficient because of some of the differences in construction compared to my other driver rather than because it's a dual coil, although having both North and South of the magned up near the strings may make a difference - certainly focuses the feild better... kinda like a 'horseshoe' magnet. Keep up the good work...this is moving pretty quickly lately...by the time I get around to playing with these concepts, the hard yards will have been done! http://www.projectguitar.com/uploads/emoticons/default_biggrin.png' alt=':D'> pete I'll keep going until either we get a sustainer systems that is 'good enough', or we hit a brick wall problem. Imagine if we end up with a slimline DIY sustainer that is cheap and relatively easy to build, can be installed with no guitar mods, works well with an even response, and lasts for 30 hours playing time on a 9v alkaline battery... That would really sock it to Sust@in1ac and Fern@nd3s cheers Col Link to comment Share on other sites More sharing options...
Robert_the_damned Posted September 22, 2006 Report Share Posted September 22, 2006 Hi guys I've been following the thread reacently and I've been getting lots of ideas so I thought I'd help out. Here's Onelastgoodbye's driver done on FEMM...I'd be happy to do other drivers too if its needed. one thing of note: I did two versions one with the laminated cores and one with solid ones of the same shape, The laminations seem to focus the field a little so maybe that's something else to consider. I'm still thinking about a hex design but it'd be going on the same guitar as my home brewed MIDI system (still in the early stages too) so I'd already have a hexaphonic pickup signal the thought of making a hexaphoic humbucking driver is giving me a headache already though! Robert Link to comment Share on other sites More sharing options...
Robert_the_damned Posted September 22, 2006 Report Share Posted September 22, 2006 Col posted whilst I was posting obviously! here is his driver as it stand and his original design (magnet thickness estimated to be 5mm I'll refine it if nessicary). These were done with ceramic magnets as I couldn't remember what type he'd been using. cores are pure iron in both cases as I've not read exact material specs. his driver as it stands: and original design: Link to comment Share on other sites More sharing options...
col Posted September 22, 2006 Report Share Posted September 22, 2006 Col posted whilst I was posting obviously! here is his driver as it stand and his original design (magnet thickness estimated to be 5mm I'll refine it if nessicary). These were done with ceramic magnets as I couldn't remember what type he'd been using. cores are pure iron in both cases as I've not read exact material specs. Magnet thickness is 3mm (a little over), material is alnico cores I think are some sort of steel - called 'flat-iron' in the shop, but it said 'drawn cold steel' on one of the shelf labels, so who knows. Looks like I need to reduce the width. what would it look like with a 8mm gap between the cores, with a 6mm wide ceramic magnet with a 1mm spacer on each side - spacer material is up to you . Top of magnet is 4mm from top of cores. cheers Col Link to comment Share on other sites More sharing options...
Robert_the_damned Posted September 22, 2006 Report Share Posted September 22, 2006 I've re-drawn the first two I did for your drivers Col, I used a pretty generic low carbon steel so it should be pretty representive (I don't think it makes a big differance to be honnest) and the one with the spacers (I used copper but it shouldn't really make any differance between differant non-magnetic materials): could have told you that result without simulating it. Dimarzio use exactly this spacing technique to make ceramic magnets have the same strength as aged alinco (used in the 'air' series of pickups). I have the sneaking suspision I didn't swap the ceramic for Alnico now....ah hell! Link to comment Share on other sites More sharing options...
col Posted September 22, 2006 Report Share Posted September 22, 2006 could have told you that result without simulating it. Dimarzio use exactly this spacing technique to make ceramic magnets have the same strength as aged alinco (used in the 'air' series of pickups). hmm, interesting... what happens if the spacers are steel ? This process will soon have the page count flying up @pete Thoughts on EMI 'fizz' Been thinking about this some more, and I'm not so sure now about the earth being a problem... I tried again holding the driver above the strings, and the problem seems to be completely dependant on where the driver is in relation to the pickup. If it was an earth related issue, surely the fizz would be there wherever the driver is placed? Col Link to comment Share on other sites More sharing options...
Primal Posted September 22, 2006 Report Share Posted September 22, 2006 Robert, you do know that there is a picture posting rule here, right? Those are WAY too big (almost fill up my 1440x900 19" monitor) and you are only allowed to have one picture per post. Link to comment Share on other sites More sharing options...
spazzyone Posted September 22, 2006 Report Share Posted September 22, 2006 I get a small amount of "Fizz" but its not from the sustainer its my pickup. It was a dimarzio double whammy now a jackson j50. the fizz was gone with rolling back the volume. And it happend with or without the sustainer. Thats why i switched to the lower output pickup. The system im using does not work as well in the middle position Emi is not the problem just does not sustain as well. And reversing phase changes nothing for me (not sure why). The rail has worked better than all the drivers i have made including the bilateral so i must agree with Pete that a rail is better. But i also think the rail is not he best solution. as it has a north and south polarity. of all my home made drivers though this worked the best. I have since gone back to the rail in the neck and humbucker bridge. It just works the best. And a laminated core also worked a little better as i could focus more energy on the higher strings. My latest tweaking has been to design as driver that was S/N/S polarity the thought being on a strat the magnet polarity including its own bridge and neck pickups would be S-S/N/S-S thus traping the EMI feild. Does this sound correct? Link to comment Share on other sites More sharing options...
psw Posted September 22, 2006 Author Report Share Posted September 22, 2006 Robert, you do know that there is a picture posting rule here, right? Those are WAY too big (almost fill up my 1440x900 19" monitor) and you are only allowed to have one picture per post. Primals right...we do get away with it a little bit more than we should, but most posts are text... Check out your picture hosting site, photobucket has a resizing option...if you resize those pics it will become smaller... Since you are doing them a little faster than I could...here is the dimensions of a rail pickup... The blades are pretty thin and for the driver they may need to be extended another 3mm (I wonder if it will fit in the guitar if it is this tall?)...anyway, if you've a mind to, it would be interesting to see how a magnet that far below the driver inter-reacts... Another thing that has just come to mind about my guitar after looking at these, that may have some impact...it is a strat copy...between the driver and the bridge pickup is a middle pickup. While the sustainer is on, it is disconected but it's magnetic influence will still be there and may be sheilding the bridge pickup a little... pete Link to comment Share on other sites More sharing options...
psw Posted September 23, 2006 Author Report Share Posted September 23, 2006 Good Morning Gentleman...5am Sunday and time to go to work...grrr Anyway...I mentioned something that come to mind in looking at the FEMM diagrams. These are not really representative of what really goes on of course, but does give some idea...and can be a springboard for ideas, and FEMM is worth playing around with... So...if you took a rail driver and combined the magnetics of a bi-lateral driver...what would you have? Basically, you could have two full length coils as on a rail but only magnetise the bass on one and the treble on the other, this would give you some degree of separation and a narrower driving core effectively...while still maintaining the EMIbucker qualities. It is just an idea...it may not be as efficient...but it could also provide better separation if we were to try to run the thing in stereo for better polyphonic drive... pete Link to comment Share on other sites More sharing options...
onelastgoodbye Posted September 24, 2006 Report Share Posted September 24, 2006 wound another coil; had another short so I did a little research instead: http://www.q-tuner.com/index.shtml These pickups have intrigued me for a while, but I'm just now starting to understand what it's all about. I'm gonna try to build a driver in a similar configuration, not in the least because it looks so cool (I love a product that displays it's inner functionality). Here's a little bit of my train of thought ( if you don't like blabber, you've been warned ) looking at the FEMM diagram of my own coil a few posts back, it suddenly struck me that the inner windings of the coils (the windings that sit in between the core) sense a stronger magnetic field than the outer windings, and thus probably put out a stronger voltage when the field is disrupted. So why not place the whole coil in between the cores? mmm...and to make things more compact, in width (I've suddenly become a follower of the narrow driver theory) we could rotate the coils 90 degrees, you know, put them on their sides. Electromagnetically speaking, there's no reason why a coil should be wound around the core, or why a core should be physically connected to the magnet. For a current to be induced, the coil merely needs to sit in the magnetc FIELD of the magnet, parallel to the core (as in not perpendicular). mmm...didn't fernandez put their early drivers on their side (the coils, that is)? now why'd they do that? Ooo...(eureka!) it's probably to reduce electromagnetic interference with the pickup; just like why they mount amp transformers at straight angles to one another. Magnetic fields placed at 90 degrees have little to no influence to each other. Now, in the Fernandes sustainer's case, the fields of pickup and driver would still be orientated the same way, but atleast the coils of driver and pickup would not be, so the transformer effect would be minimal...i think..gah, need to find my engineering handbook..it's lying around here somewhere (yeah, I actually tried engineering some 7 years ago, we spent a whole semester on electromagnetics. can't remember crap of it though). So what do we have. 2 coils on their side each 2 mm thick. 2 blades each 2 mm thick (maybe we could get away with 1 mm). So that's a total width of 6 - 8 mm. Cool. 'height' of the coil would be about 5mm, if I adapt the jig maybe even less. Leaves us with the biggest hurdle, the magnets. I've got some u-channel iron bar here, bet there's some nifty neodymium mag configuration possibilities there.. Link to comment Share on other sites More sharing options...
Primal Posted September 24, 2006 Report Share Posted September 24, 2006 I really don't think you are going to get a good driver by putting the coils on their sides. Thing about how a solenoid works. When you wind a coil around a magnetic (not magnetized) coil and run electricity through it, it moves in either one direction or the other. This is the same concept behind the driver. With these drivers, the magnetic field is strongest at the top and bottom of the coil (i.e. the open ends). If you put the coils on their sides, you are going to be putting the strings in a very weak (coil induced) magnetic field, thus you would need to run the whole sustainer at a MUCH higher power, thus negating any EMI advantage (which I'm skeptical of anyway) not to mention having to figure out how to power it. One more thing about the magnetic field, the magnets are just there to provide a latent field for the driver to work against. Link to comment Share on other sites More sharing options...
psw Posted September 24, 2006 Author Report Share Posted September 24, 2006 wound another coil; had another short Hmmm...something not right there...I never had that problem, seriously...perhaps it's the jigamathingie?! Anyway...you are both right and wrong...primal is right...and yet... The above is a pic of the short lived side driver idea fernandes had. There are a few problems... First...be wary of the q-tuner guy. I have his book "Animal Magnetism" though...and it certainly has some food for thought and some great construction tips and epoxy molding strategies...there is some doubt about the theory and I am not entirely convinced about the end result. Gibson has had sideways coils too by the way (grabber bass comes to mind) and I think there may be a few more...Lace perhaps... Anyways...it is not just simply two coils tipped on their side. I used to have the patent printed out somewhere and I may try and draw it up. The magnetism does need to run through the coils and is magnetised through it. The fernandes driver is arranged so that there is a centre blade magnetised north, and two side blades magnetised south. The cores run through the coil then 90 degrees towards the strings (so there may be a use for the U shaped steel. I will have to look it up and draw a picture... As to it's benefits, or not. There will still be EMI but it will help a lot (I used similar ideas in the HEX drivers), but notice it is now not an oval pickup shape, but a rectangle! By necessity, the main part of the core will be well below the strings as well as most of the coils...as Primal observes...although it would work...it may need an increase in power and as a result undo the EMI savings you at first achieved (fernandes ran this system on 18 volts as I recall!). There may be a reason why they didn't persist in this, there may have been patent reasons for a novel design also (for novelties sake alone ) It is something to consider or maybe even try, but I think a thin coil very close to the strings and aiming right at them is more the ticket... If you want to get crazy...I could develop my ideas for a "wave" driver that runs parrallel to the strings...but that might just get a little weird, and we have been going so well lately... I think a thin driver rail system still holds a lot of promise and needs to be explored a little more...perhaps the bi-lateral magnetics on a rail design would give you the best of both worls...very thin active cores and only one per string, and yet full width EMI reducing coils... And of course...all the variations we haven't come up with yet!!! pete PS...love your work as always Tim... p Link to comment Share on other sites More sharing options...
psw Posted September 24, 2006 Author Report Share Posted September 24, 2006 Let’s all praise Kenji Tumura, Osaka, Japan… Obviously he was the one charged with putting considerable thought into designing stuff for Fernandes over the years…including this sideways driver… Anyway…check out patent 5,585,588 Patent Link - 5,585,588 I discovered what had gone wrong with my web browser…apple’s quicktime took over the image control of the TIFF images at USPTO and as a result, would not allow me to print or save stuff unless I paid for a “pro” version… Strange…cause I used to be able to with the View recommended by the office AlternaTIFF…fortunately, I have got it back under control… Patent 5,585,588 has some interesting stuff…it is not entirely clear how the magnets are placed, but here is a cross section from page 9 of the images… I will have to look a little further into how the magnet is done…unless you guys would like to try… There are also interesting ideas (not sure how worthy) ways of cutting the blade(s) so that each string has a drive bias and this idea for a shunting piece to shorten the drive area for higher strings (in line with my thin core theories for higher strings, I’m pleased to note!) Impressive as these may seem...I don't see any evidence of the two former ideas being used by fernandes (although Sustainiac (hoover)) did suggest something similar that we discussed a loooong time ago, there is no evidence of them being evident in the final product. (see the photo in the above post...see any blade slits or shunts?) And of course, fernandes abandoned the sideways driver concept...so, a grain of salt as always... Even though Mr Tumura has some impressive ideas that we can learn from...presently most seem to be going along with my thin driver/simple amplification model of addressing sustainer technology. I don't think anyone has come up with another suggestion (except perhaps spazzys heavily amplified pickup) that has yeilded such results without going into a lot of amplification compensation circuitry (as is outlined by Mr Tumura in his patent also)...without sounding too vain... The rail driver elaboration, not withstanding! One thing that has always puzzled me... Why are the coils in these sustainers always so big?! Is it just a coinsidence that they appear the size of a standard pickup...is there perhaps some conservatism and expectaion of size that has lead them to these dimensions perhaps...or am I missing something. As much of a blind alley the Hex designs may have proved to be...at the very least, they broke the dimensional barrier that led to the thin driver principle...hahaha pete Link to comment Share on other sites More sharing options...
onelastgoodbye Posted September 24, 2006 Report Share Posted September 24, 2006 Hmmm...something not right there...I never had that problem, seriously...perhaps it's the jigamathingie?! Afraid so.. the epoxy sort of sticks to the aluminium (which it shouldn't be doing, damn disobedient epoxy). It's just a little mechanical stick, but enough to break the windings at the core edges when i unclamp the jig. Probably neet to let it cure a little longer, or use a cheap release agent (vinyl tape, maybe shoe polish?) I really don't think you are going to get a good driver by putting the coils on their sides. I got a bit carried away there. It got late yesterday night . I'm aware of the solenoid thing and how a coil with core inserted is dramatically more effecient than a coreless coil, yet somehow managed to forget that little fact (never was much of an engineer, i'm more like a mad professor ). Anyways...it is not just simply two coils tipped on their side. I used to have the patent printed out somewhere and I may try and draw it up. The magnetism does need to run through the coils and is magnetised through it. The fernandes driver is arranged so that there is a centre blade magnetised north, and two side blades magnetised south. The cores run through the coil then 90 degrees towards the strings (so there may be a use for the U shaped steel. I will have to look it up and draw a picture... Yeah I read about the polarities..I'm having a bit of trouble imagining how that configuration affects the magnetic field through the coils. Does one coil still 'see' north polarity, the other south (to take care of the humbucking)? right hand rule and all that stuff... One thing I should note is I was thinking more of a configuration like the q-tuner, with the magnets inside the coils (seems like that's what he's doing), so the coils wouldn't exactly be core-less. Not sure on how the magnets are polarised though. Vertically or horizontally? btw, I'm also pretty convinced our 'regular' rail driver is the way to go (hard enough to build as it is), but I figured these side coils might be worth exploring so thought i'd "throw it into the group" (is that a valid saying in english? it is in dutch ). If someone can shed some light on the polarity thing, I'd might just be able to make something really simple (construction wise) using the u-bar: winding two coils around the magnet and putting that in the u-bar. I'd like to try the u-bar for shielding purposes but I can oly put two coils in if they're on their sides. Anyway, as Primal said, efficiency is probably gonna be pretty bad with side coils anyway. Here's another brainteaser: I don't suppose anybody has ever tried bismuth as a shield? Link to comment Share on other sites More sharing options...
onelastgoodbye Posted September 24, 2006 Report Share Posted September 24, 2006 Patent 5,585,588 has some interesting stuff…it is not entirely clear how the magnets are placed, but here is a cross section from page 9 of the images… I will have to look a little further into how the magnet is done…unless you guys would like to try… that's exactly what I had in mind (only a lot smaller)! if you look at fig.14 and 15, which are the sectional view and top view of the same driver, you can see that the magnets (indicated by nr. 83) are sitting inside the coils, inbetween those two screws that are used to hold the whole thing together. Polarity of the magnets must be horizontal. Seems like those screws also function as a connection for the coil leads? Link to comment Share on other sites More sharing options...
psw Posted September 24, 2006 Author Report Share Posted September 24, 2006 I suspect Master Tumura's mind works in mysterious ways!!! Perhaps those screws do hook the thing up...they certainly help hold the thing together, and gave me a good idea...must sleep though 5 hours till work again at 4 am....eeek! Polarity of the magnets must be horizontal. Yes...but along with the blades make a kind of double horseshoe effect directing the field up towards the string. I think the most valuable part is not that the coils are on their side (because the blades diret the energy up anyway...but their is an active south shield on either side of the north centre core. The whole thing may end up functioning as a wide core though...except for the shunting...and so go against the thin core theory...as does the rail driver to a lesser extent... I think epoxy is a worry...it's great when it works, and required for a truely bobbinless driver...but don't your fingers stick together? One thing I should note is I was thinking more of a configuration like the q-tuner, with the magnets inside the coils (seems like that's what he's doing), so the coils wouldn't exactly be core-less. No..and neither are this driver's...his book (forgotten his name...shows several types of sideways and stacked and even individual coil pickups...all designed for his fretless bass designs of which the construction takes up the second half of the book...must try to sleep now, but I will take another look at it.... The best part of his ideas of construction as I recall is the use of epoxy (sometimes clear) in moulds to make very profesional looking EMG-ish pickups....very neat. sleep...must sleep.. pete Link to comment Share on other sites More sharing options...
col Posted September 24, 2006 Report Share Posted September 24, 2006 ... or use a cheap release agent (vinyl tape, maybe shoe polish?) cling film (clear film?). epoxy won't stick to it, and its very thin, cheap and easy to wrap things in. col Link to comment Share on other sites More sharing options...
onelastgoodbye Posted September 24, 2006 Report Share Posted September 24, 2006 cling film (clear film?). epoxy won't stick to it, and its very thin, cheap and easy to wrap things in. *slaps forehead* ofcourse! gah I'm stupid. I used that stuff to laminate my fretboard worked my way through most of the patent..lots of useful info.Some insights and corrections to my previous posts: The screws hook up to a ground wire, not the coil wires. fig. 13 and fig. 14 are not exactly the same. the first driver (13) uses a permanent magnet as a core; the second driver (14-15) uses a combination of a smaller permanent magnet and a ferromagnetic material (iron or ferrite) as a core, which should be more efficient: Further, according to the seventh embodiment, a magnetic flux producing substance is formed by a combination of a permanent magnet and a ferromagnetic substance, and thereby, efficiency of the magnetic flux producing substance is significantly developed compared with a magnetic flux producing substance made of only a permanent magnet because the magnetic reluctance of the former is smaller than that of the latter while in operation. Yes...but along with the blades make a kind of double horseshoe effect directing the field up towards the string. I think the most valuable part is not that the coils are on their side (because the blades diret the energy up anyway...but their is an active south shield on either side of the north centre core. The whole thing may end up functioning as a wide core though...except for the shunting...and so go against the thin core theory...as does the rail driver to a lesser extent... I think you're right about the active shield thing being the most valueable part: Further, according to embodiments from the sixth to the eleventh embodiment, the electromagnetic driver has three bar type pole pieces and two magnetic flux producing substances sandwiched between them, and only the polarity of a center bar type pole piece is different from that of other bar type pole pieces on both sides, and thereby, there are several advantages in that magnetic flux is concentrated on the center portion in the neighborhood of the strings, and thereby, said magnetic flux enables a string to be efficiently excited by little electric power and so the power consumption of the dry cell battery mounted on a guitar is reduced significantly. some other interesting stuff: airgaps below the coils to prevent the field from leaking into the trem cavity: Further, according to an electromagnetic driver of a device for sustaining the vibration of a string as shown in the eighth embodiment, a Tremolo device, a spring and a metal screw form a magnetic circuit and so-called magnetic feedback is produced by magnetic flux emitted from the bottom of the electromagnetic driver through said metal devices. Downward deflecting slits prevent the production of the magnetic feedback by properly distributing downward magnetic flux. mmm...did he just patent bobbinless drivers here? beat me to it Furthermore, there is a merit in that an electromagnetic driver of this embodiment is basically formed only by processing a bar type pole piece and a magnetic flux producing substance. Therefore, there is no need of plastic mold elements such as a bobbin in the electromagnetic driver and so various widths, lengths and shapes of the electromagnetic driver can be easily realized. Also, the production of the electromagnetic driver is completed by substantially fixing the magnetic flux producing substance on the bar type pole piece with a screw instead of assembling several parts, e.g., a permanent, a base plate and a cover, into a electromagnetic driver after a coil is wound around a bobbin. Therefore, the electromagnetic driver of this embodiment is very convenient for inexpensive mass production thereof. Accordingly the coil of the electromagnetic driver 17 uses a copper wire with a diameter of 0.3 mm larger than that of the electromagnetic pickup 8 and about 200 turns of the wire is wound, therefore the electromagnetic driver 17 has small electric resistance about 7 ohm and low power-loss characteristics. that explains the big coils...BIG difference between 0.2 and 0.3 wire...see page 103 of this thread . Col, you'll like this one... A driving current used to excite a string in such an excitation system is usually about 50 mA, and so the emission efficiency of driving magnetic energy is very important so as to prevent the necessity of frequently changing the dry cell battery. Link to comment Share on other sites More sharing options...
spazzyone Posted September 24, 2006 Report Share Posted September 24, 2006 What all this shows is exactly what was in my last post to some degree that is the S/N/S polarity driver. When droped in a standard srat would magneticly read S-S/N/S-S. this would be pickup/driver/pickup common sense tells me this should trap EMI. And maybe even reduce single coil hum. The last few post all show this in one form or another. My uncle has a machine shop and im gonna see if i can get in there and make that Fernandes sideways setup. But make a one peice three blade polpeice that would have two magnets and two coils like the fernandes not sure how this will work but worth the try. This would give me the S/N/S that im thinking of Anobody think this is worth the effort? Link to comment Share on other sites More sharing options...
psw Posted September 24, 2006 Author Report Share Posted September 24, 2006 OHhhhhhhHHhhHHH....4 hours slepp....what a nightmare, not only is it back to work again....but now the thread's degenerated into "patent-speak" (pat pend) I have read most of the Sustainer Patents (unless I missed something) and the whole patent process produces some of the most bizzar statements...some very misleading and others...well just silly and put in there just because the previous one did. I found a "sustainer" patent from the late 19th century you know, the idea has been around a long time. Heet, in the ebow patent just had a pickup and driver with an amp between...Floyd Rose had phase circuitry included...Hover (sustainiac) showed a bobbinless driver in the bi-lateral device...Fernandes (Tumura) tiped a stacked pickup on it's side... I suspect a little tit-for-tat... To get a patent you need to match and exceed in novelty those patents that have gone before it. You also need to express it in such a way that a] no one will understand what it is you are saying, and b] say it in such a way that the next person will have to come up with even more novel approaches to warrant it as a "new" idea!!! a] is important so that people can't copy you, b] so that other's can't patent anything even like it, or on the same principle...protection and covering all bases... Anyway...a lot more progress is gained by being aware of the principles of the technology and experimenting with it than what the patents reveal...as we have been doing. It would be better if these guys were to make their research open (surely they tried the rail driver idea) so that we wouldn't keep trying out things that have failed before. But then, maybe they missed out on some key element (thin drivers, thinner wire, etc) that could have made it work. I don't recall ever seeing a stacked driver...hmmm So...bobbinless coil...check, both hoover and tumura propose this possibility. Trem as a magnetic sink...well, it is under there so it can't really be avoided and would function like this with any system (so, I they have patented the inevitable!)...but wait, this is wired to the guitar's ground, couldn't this be a problem...hmmm and this... thereby, there are several advantages in that magnetic flux is concentrated on the center portion in the neighborhood of the strings, and thereby, said magnetic flux enables a string to be efficiently excited by little electric power and so the power consumption of the dry cell battery mounted on a guitar is reduced significantly. thereby the active part of the coil is forced well below the string itself (by the bulk of the coil)requiring more power (perhaps) that a simple single coil mounted right up against them...errr...thereby... Hey it's a neat idea, let's talk it up as best we can... Accordingly the coil of the electromagnetic driver 17 uses a copper wire with a diameter of 0.3 mm larger than that of the electromagnetic pickup 8 and about 200 turns of the wire is wound, therefore the electromagnetic driver 17 has small electric resistance about 7 ohm and low power-loss characteristics. Yes and very different resonant frequencies...hang on, thicker wire, less resistance, less responsive, more circuitry required...why not use 0.5...oh yeah, at the powers in a battery it may barely make an adequate field, let alone alter it at the frequencies required...perhaps that is why fernandes ran this thing off two batteries!!! Ohhh Noooo...my cynical side has come up...more sleep required...or work...d'oh! pete Link to comment Share on other sites More sharing options...
psw Posted September 25, 2006 Author Report Share Posted September 25, 2006 Well that was a long day... I was thinking...with all this talk about new drivers and such, we shouldn't loose sight of what we have. The basic "thin driver" is not only simple, it's compact size is a key factor in it's efficiency, reduced EMI output and makes for a very versitile unit (as featured on my guitar) due to it's...well...thin-ness There are more things you can do to improve things further...a metal or magnetic shield around it for instance... The thin core inheirently bias's in favour of the high strings and supplies some balance to the lower strings at the same time. I think there is a lot of merit in the thin core theory and new designs should make some attempt towards this end. But I am intrigued by the rail driver. I think you could make a rail driver which combines both by having a "split blade". By this I mean, on one coil a magnetic core under the high strings, on the other the low strings, with a dummy non-magnetic core on the other half. You would still be driving from a single thin core but have the benefit of two full length EMI reducing coils. The result would be the best of the bi-lateral, rail and current "thin driver" ideas. Of course, this would be subject to testing as to it's efficiency, but such a device could open the way for some kind of stereo amping or simple circuit biasing for each coil taylored to it's given strings...possibly better polyphonic response too! We should be looking at efficiency and EMI reduction. Dizzy has shown that a mid coil driver is possible, I'd certainly like to be able to achieve this, and EMI reduction will be crucial for this. I think we should also consider a humbucker sized pickup/driver device... As for the circuitry...I'm thinking of experimenting with some stuff in modular form. Placing the poweramp (LM386) section close to the driver itself has some major advantages and can be made very small. I like the idea of buffering the guitar signal as well as a preamp for the sustainer. This itself may be enough...but then, between this we could experiment with such "conditioning" circuits as col has suggested. Anyway...lots to think about, plenty to do. Keep up the work, I hope to ride your coat tails ASAP! pete Link to comment Share on other sites More sharing options...
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