Patent Application
20200234685
Other than for confidential and/or necessary use inside the Patent and Trademark Office, this authorization is denied until the Nonprovisional Patent Application is published, at which time it may be taken to state:
The entirety of this application, specification, claims, abstract, drawings, tables, formulae etc., is protected by copyright: © 2020 Donald L. Baker dba android originals LLC. The (copyright or mask work) owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all (copyright or mask work) rights whatsoever.
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https://www.researchgate.net/profile/Donald_Baker2/projects
This application is related to the patents and applications cited above for benefit, and discloses additional embodiments especially relating to U.S. Pat. No. 10,380,986 (Baker, 2019 Aug. 13), filed by this inventor, Donald L. Baker dba android originals LC, Tulsa Okla. USA.
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This invention describes electro-magnetic string vibration pickups, primarily used in guitars and basses, also applicable to other musical instruments with ferrous strings, such a pianos, to be used in humbucking circuit arrangements in which each pickup responds equally to external electromagnetic fields, otherwise known a hum. It can be made to apply to other sensors, such as piezo-electric, hall-effect and strain gage.
This inventor was not able to find original patents for the standard 3-way switch commonly used on dual-humbucker electric guitars, or for the common 5-way switch commonly used with electric guitars having 3 single-coil pickups. According to O'Connor (2016, p 1036, citing http://alloutput.com/guitar/5-way-switches-explained/) players found they could balance the 3-way switch of the 3-coil Fender Stratocaster™ (released in 1954) between positions to get sound from two pickups at a time. O'Connor claims that the sounds of the 2-pickup combinations were out-of-phase and weak. If that is so, then at some time later Fender reversed the connections and/or pole on the middle coil to obtain in-phase tones, but his inventor has not been able to find a reference. O'Connor (p 1036) claims that Fender introduced the 5-way switch sometime in the 1970s to 1980s. Gagon et al. (U.S. Pat. No. 4,545,278, 1985) and Riboloff (U.S. Pat. No. 5,780,760, 1998) use the standard 5-way switch and a variant to switch 3 single coils, with all the coils connected by one terminal to ground. But they focus mostly on tone.
Baker (U.S. Pat. No. 9,401,134, 2016) used two 4 pole-5 throw “super-switches” to combine 4 matched single-coil pickups into 4 humbucking pairs, and 1 humbucking quad, with separate switches for series and parallel pickup circuits. Columns 18-19 specifically disclose the nature of humbucking pairs. Ignoring SW1 and SW2,
Seeing that many patented pickups circuits threw switches at the problem without bothering to check for duplicate circuits, Baker (U.S. Ser. No. 10/217,450, 2019, filed 2017 Jun. 7) systematically constructed and enumerated series-parallel single-coil pickups circuits, up to 6 pickups in size (disclosing up to 5), then substituted series and parallel humbucking pairs with matched single-coil pickups for the previously constructed single-coil pickup circuits, disclosing humbucking circuits up to 6 pickups.
Baker also discovered a 3-coil humbucking circuit in U.S. Ser. No. 10/217,450, which became the basis for humbucking circuits of any number of 2 or more of matched single-coil pickups, in a patent application filed 2018 Sep. 22, published as US 2019/0057678A1, 2019 Feb. 21, which became U.S. Pat. No. 10,380,985 (Baker, 2019 Aug. 13). This patent established that there is no need to reverse-wind pickups with reversed magnetic poles, when it is simpler just to reverse the pickup terminals. Humbucking is not affected by the pole orientation of the magnet, but by the connections of the coils. To hum, the magnet is just another magnetically permeable structure.
U.S. Pat. No. 10,380,986 discloses the common-point connection switching system, where all the pickup are connected to a single point by their terminals with the same phase of hum voltage. The other terminals of the pickups are connected either to the high or low output terminal, or no terminal. At least one pickup must be connected to each output terminal. This cancels hum, regardless of the number of pickups (greater than one) connected between the common-point connection and each output terminal. If more than one matched pickup is connected between the common point and an output, then the effective output from those multiple pickups is the average of their signals, the total divided by their number. Either the common-point connection is grounded, or the low output terminal is grounded, but not both. The resulting circuits are all humbucking, but do not include all of the possible humbucking series-parallel circuits of matched single-coil pickups. Nevertheless, this simplifies pickup switching and still provides more combinations that standard 5-way switches. For common-point connection circuits of 2, 3, 4, 5 and 6 matched coils, there are 1, 6, 25, 90 and 301 possible different circuits.
SW1 and SW2 in
We will see from later Figures that SW1 is overkill. For the most common of electric guitar outputs, single-ended with SW2 down, where the lower output is always grounded, SW1 need only have two throws, open and ground. For multiple pickups, allowing SW1 to have three throws only produces a set of outputs for the third throw that are all duplicates. To minimize noise, SW1 should preferably be either open or grounded.
The closest patent this inventor could find that has some features of this invention is U.S. Pat. No. 4,151,776, Stich, 1979. Like U.S. Pat. No. 4,545,278, Gagon, et al., 1985, and U.S. Pat. No. 5,780,760, Riboloff, 1998, it has 3 single-coil pickups connected together at a common point, but it is not always grounded. It has a number of errors and Stich did not fully recognize or utilize the potentialities of that arrangement. The common point is grounded only when switch 52 is in the 1-position, and then only to obtain the single output of the bridge pickup (24); in that condition, none of the positions of the 3P4T switch 50 have any effect on the output.
When switch 52 is in the 2-position, the common point is ungrounded and switch 50 has 4 humbucking outputs, but Stich does not recognize them all as humbucking. For N being the neck pickup, M being the middle pickup and B being the bridge pickup, for positions 1 to 4 switch 50 produces, respectively, N+M, M+B, (N+B)/2+M and N-B. One has to suppose that these are the outputs, because Stich does not specifically identity this circuit set as humbucking, only stating that humbucking occurs. In Col. 1, lines 20-25, he states that two coils are “wound in opposite directions” to achieve humbucking, and then in Col. 5, lines 43-46, wrongly states that the humbucking out-of-phase combination, N-M, cannot be humbucking because the coils are wound in the same direction.
Throughout the patent specification, Stich attributes humbucking not to circuit connections but to pickups wound in opposite directions, apparently not recognizing that the same effect can be realized merely by reversing the connections of one of two coils wound in the same direction. Over the years, a great many guitar patents have made this conceptual mistake, apparently derived from the very first pickup humbucking patents, showing coils with different poles wound in different direction, i.e., U.S. Pat. No. 2,026,841, Lesti, 1936.
When switches 50, 52 and 54 are in positions 3, 2 and 1, Stich's circuit does achieve a humbucking triple. But this is hindsight; Stich does not claim or recognize it as such. In Claim 1, Stich refers not to any humbucking triple, but to separate signals from neck and middle and from the middle and bridge directed to output channels 1 and 2. Claim 3 incorrectly ascribes the 4th position of switch 50 to connecting all three pickups together.
These facts clearly demonstrate that despite any similarities in circuit construction, Stich's patent cannot anticipate what Stich, or anyone else, neither saw nor taught nor claimed. Instead, Stich produced a circuit with 4*2*2=16 different combinations of switch positions with only 5 tonally distinct outputs. This inventor developed this invention independently of Stich, and found the Stich's patent to have similarities after the fact.
In another patent application U.S. Ser. No. 15/917,389, 2018-07-14, Baker disclosed that merely reversing the magnet in a humbucking circuit changes only the phase relation between pickups in the circuit, without affecting the humbucking nature of the circuit. For J number of matched single-coil pickups in a humbucking circuit, there are then 2J-1 number of different combinations of phase tonality, each sharing some tones with each other. In more recent calculations for a textbook, for common-point connection circuits of 2, 3, 4, 5 and 6 matched coils, there are 2, 18, 92, 540 and 1640 different tone circuits with reversible magnets. This patent application will reinvestigate if the number is correct for 3 matched coils, since math errors are always possible. Note however, that tones tend to bunch at the warm end, and there will be fewer tones that can actually be distinguished from one another.
It is not possible in most cases to achieve a full set of possibilities with mechanical switches, but in patent applications previous to this, Baker underestimated what could be done. This patent application offers more embodiments to the common-point connection switching system of U.S. Pat. No. 10,380,986, which takes advantage of improved switching design, based on
This invention derives directly from U.S. Pat. No. 10,380,986 (Baker, 2019). Primarily, it makes better use of the mode switches, SWa and SWb in FIG. 17 of U.S. Pat. No. 10,380,986, and similar functions in SW1 to SWj+k in the same Figure to provide a better-organized and expanded set of outputs for sets of either 3 single-coil pickups or 3 dual-coil humbucker pickups, in such a way that all of the electro-mechanical controls will fit on a standard-sized electric guitar. In addition, the expanded use of mode switches allows 3 dual-coil humbuckers to partially simulate 3 single-coil pickups with reversible magnets to see what kind of tonal options might result, and justify the inventions in NPPAs Ser. No. 15/917,389 (Baker, 2018), Ser. No. 16/752,670 (Baker, 2020) and Ser. No. 16/812,970 (Baker, 2020). While the invention can be extended to more than 3 pickups with the switch concatenation disclosed in FIG. 19 of U.S. Pat. No. 10,217,450 (Baker, 2019), the digital-analog switching in U.S. Pat. Nos. 10,217,450 or 10,380,986 would be more practical.
Baker underestimated the number of possible switching configurations that could be achieved with the common-point connection system using mechanical switches. Then realized (from a test configuration for U.S. Pat. No. 10,380,986) that violating the rules, and connecting the common point to either terminal of the output would allow a 3-coil circuit (with 6 humbucking choices) to present the musician with the non-humbucking outputs 1-pickup and 2-pickup combinations as well. Then realized that in doing this with 3 humbucking pickups, it could simulate tonal circuits for matched single-coil circuits with reversible magnets, and with a simple switch, could provide 9 different single, pair and triple combinations of 3 humbuckers as well. This allows investigation of the concepts of U.S. NPPA Ser. No. 15/917,389 before committing to any manufacture of pickups with reversible magnets.
These embodiments derive directly from U.S. Pat. No. 10,380,986 (Baker, 2019). Primarily, they make better use of the mode switches, SWa and SWb in FIG. 17, and similar functions in SW1 to SWj+k in the same Figure to provide a better-organized and expanded set of outputs for sets of either 3 single-coil pickups or 3 dual-coil humbucker pickups. In addition, the expanded use of mode switches allow 3 dual-coil humbuckers to partially simulate 3 single-coil pickups with reversible magnets to see what kind of tonal options might result, and justify the inventions in NPPAs Ser. No. 15/917,389 (Baker, 2018), Ser. No. 16/752,670 (Baker, 2020) and Ser. No. 16/812,970 (Baker, 2020). Most of the embodiments use a 3P6T switch to make pickup circuit connections, to simplify the circuit. They are actually based on a common, inexpensive 4P6T rotary switch. The uses of the 4th pole were covered in FIG. 17 in U.S. Pat. No. 10,217,450 (Baker, 2019) and in FIGS. 7, 8, 10 & 11 in U.S. Pat. No. 10,380,986, and are discussed again in Embodiment 5 below. The more common 5-way switch used in electric guitars has an inexpensive 4P5T cousin, which can also be used, if one related set of humbucking/non-humbucking choices is eliminated.
In addition to the circuit connection switch, all of the embodiments use a main mode switch, of at least 1 pole and 2 throws. This switch chooses between 2 sets of 6 distinct circuits each, humbucking and non-humbucking for single-coil pickups, by either shorting or not shoring the common-point connection to ground. For circuits of matched, single-coil pickups, the non-shorting, or humbucking, position lets the connection switch choose between 3 humbucking pairs and 3 humbucking triples, in which all the pickups connected between the common point and ground are single pickups, and all those connected between the common point and the output high terminal are either single pickups or two pickups in parallel. The shorting or non-humbucking position shorts out all the single-pickup choices to ground, limiting the chosen circuit to distinct single-pickup circuits or two pickups in parallel.
This is modified in Embodiment 2, in which added poles on the mode switch change two of the pairs from non-humbucking to humbucking, at the expense of duplicating two tones in the non-shorting mode. In Embodiment 3, 3 dual-coil humbucking pickups are used, providing 12 all-humbucking choices for both positions of the mode switch. In Embodiment 4, additional mode switches allow the dual-coil humbuckers to act like single-coil pickups with either magnetic pole up.
Now consider the three pickups represented by coils N1 (neck), S2 (middle) & N3 (bridge) in
A Windows program, SpecAn_3v97c.exe (Speer, 2001-2016), produces FFT spectra from an audio signal to the sound board mic input. These outputs were analyzed with this program with the following settings: 135 dB log audio scale; zero weighting; log frequency scale; display set to spectrograph w/ averaging; 8 kHz sample rate; 4096 FFT size (˜2 Hz wide bins); and the Hanning window. The program produces an output amplitude spectrum with 2048 values about 1.95 Hz apart, rounded to from 0 to 3998 Hz. The outputs were generated by strumming all six strings over the middle pickup five times at about once per second, with no fretting. When the signal had significantly decayed, the sampling process was stopped, and the data saved. It produced on the order of 50 FFT windows, all averaged together, lasting 12 to 15 seconds. Imported into a spreadsheet, the data was processed according to Math 8 in U.S. Pat. No. 10,380,986 (col. 20), reproduced here as Math 1, to give the relative signal amplitude and the mean frequency in Hertz.
Now suppose that we wire the throw connections of the unfinished switch, SW3, in
Table 2 shows a better result with 6 fewer outputs. It shows the same sequence of humbucking mean frequencies for SW3 Throws A-F, but with the circuit inverted at throws A, D, E & F, so that when the common point is connected to the lower voltage output, the non-humbucking combinations in the Upper set do not repeat. Note that a number of minus signs have been removed. For example, Throw A should show −S2 and −N3, but the inverse signal (S2+N3) is used, because no one has shown that human ears can tell the difference. But while the lower non-humbucking mean frequencies are generally to the left, with higher to the right, they are not in order. It is generally not possible to order both sets of frequencies with this kind of mechanical switching. You can order one or the other, but not both.
As noted already, this use of mean frequency of the amplitude spectrum may not be the best measure of perceived tone. Human perception of tone is complex, being dependent upon both the frequency and amplitude of adjacent signals, as well as the harmonics present. But when a better measure becomes available, the ordering of tones can be easily redesigned or rewired on the switch.
Note that in Table 2 and
Suppose now that instead of 3 matched single-coil pickups,
Table 3 shows the possible connections of three humbuckers in a common-point switching system with a mode switch to short the common point to one of the outputs, along with the relative amplitude and mean frequency (Hz). The signal spectra were generated and calculated by the same methods as before, except that in this case, spectral outputs of less than 70 Hz were discarded by calculating Math 1 for 37≤n≤2048.
Note that three of the mean frequencies, 617, 621 and 629 Hz, are very close together. When the prototype guitar switching circuit disclosed in Embodiment 2 was played, Not only were two nominally humbucking signals in the equivalent 5-way switch set, (S2+N3)/2 and (S2+N1)/2, duplicated in the humbucking set by (S2+N3) and (S2+N1), but two of the humbucking signals sounded a lot alike. This meant that there were only 9 or 10 distinct tones out of the 12 for Embodiment 2. Without further study, this could mean that those three tones for this embodiment are also very similar, dropping the number of distinct tones from 12 to 10. Note that the 1 to 1.99 spread of all-humbucking mean frequencies from 506 Hz to 1009 Hz in embodiment 3 compares roughly to the 1 to 2.28 spread of mean frequencies from 430 Hz to 981 Hz in embodiment 2, where three of the output signals are non-humbucking.
The circuit in
Reconsidering
But 96 switch combinations are not 96 different coil combinations or tones. In the shorted mode of SW8 in
When (SW8) is in the up position, shorting the common point to ground, all the switch combinations can produce only 6 different single-pickup circuits: Ns, Nn, Ms, Mn, Bs and Bn. For the pickup pairs, N∥B, M∥N and B∥M, there are the same six choices for the first pickup, and four choices for the second pickup, less duplicates, as shown in Table 4. Half the 24 second choices for duplicates, leaving only 12 distinct combinations. The other 12 combinations are merely inverted, which the human ear cannot generally detect.
Now consider the humbucking doubles and triples in
All of the possible common-point switching single-coil single, double and triple coil circuits from single coils of each humbucker were measured in the manner previously described, by strumming 6 strings above the middle pickup 5 times, while taking audio samples for an FFT program. Here again, Math 1 was modified to drop all spectral results below 70 Hz from consideration.
This embodiment represents the current limits of what a mechanical common-point pickup switching system can do, with switches and controls which can fit under the soundboard or pickguard of a standard-sized electric guitar. With a digitally-controlled solid-state analog common point switching system (U.S. Pat. No. 10,380,986, Baker, 2019), 6 coils can produce 301 humbucking doubles, triples, quads, quints and hexes, ignoring whatever non-humbucking circuits can be produced by shorting the common point to one of the outputs (preferably the ground). But presumably it still beats a 3-way or 5-way switch.
The embodiments presented above all use a 3P6T switch to produce 6 different pickup circuits, when most such switches are actually 4P6T, and 6P6T switches are more expensive, but available. U.S. Pat. No. 10,380,986 effectively covers the use of the 4th pole as gain or tone correction in FIGS. 7, 8, 10 and 11; shows a 6PXT switch for all 6 coils of 3 humbuckers in FIG. 12; and shows a 6P6T switch used for both gain and tone correction in FIG. 13. U.S. Pat. No. 10,217,450 shows the 4th pole used for gain correction in FIG. 17, and shows concatenated switches in FIGS. 16 & 19.
The resistors for humbucking pickup circuits, RG-BB A-F, are all on the left of the resistor pairs connected to the poles of SW15. The resistors for non-humbucking pickup circuits, RG-HUM A-F, all on the right. The gain of the amplifier made with U1 is Vo/Vi=Gx=(RF+RGX)/RGX, where Vi is the output of SW15. The gain is always greater than 1. The relative signal amplitudes of the pickup circuits run from 0.10 to 0.32. Say that Gmin=1.1 for a signal level of 0.32, and we want all the outputs to have the same level, Vomax. Then for each switch output signal Vix, RGX=Vix*RF/(Vomax−Vix). For Vix=0.32, RGX=10*RF, and Vomax=0.352. So for Vix=0.10, RGX=0.397*RF, and Vo=0.352. These RGX values are not likely to be common 10% resistor values, so either small multi-turn pots or resistors of higher precision will be needed. And these results can change with the distance between the poles and the strings.
The op-amp circuit isolates the output tone capacitor, CT, from the pickups, so that it cannot form any resonant peaks with the lumped circuit inductance. Therefore, if that high-frequency peaking effect is desired for tone, peaking capacitors and pots must be connected to the pickups individually, as shown by TN, TM and TB in
This application claims the benefit of precedence of the following U.S. Patents and Patent Applications: by continuation in part of U.S. Pat. No. 9,401,134 (Baker, 2016 Jul. 26), U.S. Pat. No. 10,217,450 (Baker, 2019 Feb. 26), U.S. Pat. No. 10,380,986 (2019 Aug. 13) and the Provisional Patent Application 62/835,797 (Baker, 2019 Apr. 18); and is in part related to U.S. Non-Provisional patent application Ser. No. 15/917,389 (Baker, 2018 Jul. 14), Ser. No. 16/752,670 (Baker, 2020 Jan. 26) and Ser. No. 16/812,970 (Baker, 2020 Mar. 9); by this inventor, Donald L. Baker dba android originals LC, Tulsa Okla. USA
| Number | Date | Country | |
|---|---|---|---|
| 62835797 | Apr 2019 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16139027 | Sep 2018 | US |
| Child | 16840644 | US | |
| Parent | 15616396 | Jun 2017 | US |
| Child | 16139027 | US | |
| Parent | 14338373 | Jul 2014 | US |
| Child | 15616396 | US |
