Music effect pedal assembly and power transmission and filtering module

Abstract

A power transfer and filtering module for a low frequency inductive filtering and music effect pedal assembly. The module has an input interface that supports a USB PD and a power output interface with an LC circuit therebetween. The LC circuit attenuates a signal above a predetermined frequency to reduce undesired noise. The assembly includes one or more musical effect pedals, wherein a power transfer and filter module is electrically connected between the effect pedal and a power source. Using the module can reduce or eliminate undesired noise caused by switching techniques in a USB power supply. The module may filter signals having a frequency of about 270 Hz and above.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 618,068, filed January 5, 2024, entitled "USB Power Delivery Compatible Power Supply System," the entire contents of which are incorporated herein by reference. Technical Field

[0003] The disclosed embodiments relate to power delivery systems in musical arts, and particularly to USB power delivery (PD) gateways for power delivery primarily used with instrument effect pedals, which significantly reduce or eliminate background noise associated with switching techniques in USB and conventional non-USB power supplies. Background Technology

[0004] In the art of music, musicians frequently use effects pedals to alter the sound and characteristics of their amplified instruments, such as guitars, mandolins, banjos, bass guitars, the bowed string family, wind instruments, and any instrument equipped with electronic pickups, sensors, or microphones. Such musicians typically have multiple different pedals to produce varying distortion effects. Often, multiple pedals are held together on a pedal rack, which helps the performer manage multiple pedals by securing and connecting them for use, movement, packaging, and transport without disassembly.

[0005] Each pedal must be electrically connected to a power source to operate. Historically, pedals have been connected directly, in series, or in a daisy-chain configuration via AC-DC power adapters. More recently, power modules and converters have been introduced for specific applications with effects pedals. These products may include rechargeable batteries or simply convert the input voltage from a power source (AC or DC) to a preferred output voltage. Furthermore, some products isolate current to multiple outputs and / or provide safety features such as automatic shutdown under certain conditions. With the recent emergence and widespread adoption of alternative charging and power delivery protocols such as USB, especially the USB PD protocol, modules or similar intermediate devices have been introduced to convert and deliver power from USB inputs to a usable voltage for effects pedals.

[0006] Compared to older technologies, USB PD offers several beneficial features, including enhanced power delivery capabilities compared to earlier USB specifications, and power negotiation capabilities, through which connected PD-compatible devices communicate to determine the preferred voltage level (i.e., a "handshake"). The capabilities of USB PD technology ultimately provide products with improved versatility, efficiency, and security.

[0007] In theory, any USB device with PD compatibility can be used to drive an effects pedal. Such power supplies typically include switching technology to efficiently convert an input voltage (AC or DC) to a desired output voltage required by the powered device (load). The specific requirements for powering a pedalboard are typically more stringent than the requirements for charging other electronic products such as mobile devices. The incorporation of switching circuitry provides a variety of advantages that contribute to the overall performance, safety, efficiency, and compatibility of the power supply. However, the switching circuitry required to operate a USB power supply, whether battery or AC adapter, can produce noise artifacts in the audible frequency range (approximately 20-20000 Hz). This results in undesirable background noise, such as humming, whining, pulsing, or other disturbances that are not acceptable for this application when the power supply is operated to power a musical effects pedal or any audio device using a USB power source. The background noise can be undesirably or annoyingly loud, in some cases, the noise can be so loud and disturbing that the pedal cannot be used.

[0008] Filtering solutions or circuitry for traditional non-USB power supplies have recently been developed in an attempt to remove some of the audible noise caused by the power supply. Most of these modules are configured for use with AC or DC power supplies and are not suitable for use with USB power supplies, which typically produce undesirable noise due to the required switching technology. Furthermore, all known commercial filtering module products only filter relatively high audio frequencies, which does not actually address the considerable noise in the audible range described above.

[0009] Therefore, it would be useful to provide a power delivery system for use with USB protocols, including protocols with USB PD capability, that reduces or eliminates undesirable background noise and provides safe, clean, and efficient power when used to power a musical effects pedal. SUMMARY

[0010] In one embodiment, a musical effects pedal assembly generally includes a USB PD compatible power supply, at least one musical effects pedal electrically connected to the power supply, and a power delivery and filtering module connected between the power supply and the at least one musical effects pedal. The filtering module has a USB PD enabled input interface, a power output interface, and an LC circuit between the input interface and the output interface. The filtering module negotiates power from the power supply at a predetermined voltage. The LC circuit attenuates signals above a predetermined frequency.

[0011] In another embodiment, a power delivery and filtering module for low frequency induction filtering has a USB PD compliant input interface, a power output interface, and an LC circuit. The power output interface is downstream of the USB PD compliant input interface with the LC circuit therebetween. The LC circuit attenuates signals above a predetermined frequency.

[0012] In yet another embodiment, a musical effects pedal assembly includes a USB PD compliant power supply, at least one musical effects pedal electrically connected to the power supply. A power delivery and filtering module is connected between the power supply and the at least one musical effects pedal. The filtering module includes a USB PD compliant input interface and one or more power output interfaces with an LC circuit between the input interface and the one or more output interfaces. The filtering module negotiates power from the power supply at a predetermined voltage, and the LC circuit attenuates signals having a frequency of about 270 Hz and above. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is an output spectrum plot of a USB-C PD power supply with a 20 mA load;

[0014] Figure 2 is a spectrum plot of a known product described as having power supply side filtering connected to a USB-C PD power supply with a 20 mA load; Figure 1

[0015] Figure 3 is a spectrum plot of a known product described as having power supply side filtering connected to a USB-C PD power supply with a 20 mA load;

[0016] Figure 4 is a spectrum plot of the output of a USB-C PD power supply with a 500 mA load;

[0017] Figure 5 is a spectrum plot of the output of the disclosed filtering module attached to a USB-C PD power supply with a 500 mA load;

[0018] Figure 6 is a spectrum plot of a known product described as having power supply side filtering attached to a USB-C PD power supply with a 500 mA load;

[0019] Figure 7 is a spectrum plot showing the output of an exemplary guitar pedal chain powered by a USB-C PD power supply used in Figures 1-6

[0020] Figure 8 is a spectrum plot showing the output of an exemplary guitar pedal chain powered by a USB-C PD power supply used in Figure 7 ​​Spectrum plot of the output of a guitar pedal chain used in the example, powered by a USB-C PD power supply, with the disclosed filter module connected between the power supply and the first pedal;

[0021] Figure 9 is a perspective view of a preferred embodiment of the filter module of Figure 7 and Figure 8 is a spectrum plot of the output of a guitar pedal chain used in the example, powered by a USB-C PD power supply, with a known product described as having power supply side filtering connected between the power supply and the first pedal;

[0022] Figure 10 is a perspective view of a preferred embodiment of the filter module of

[0023] Figure 11 is a top view of the PD filter module of Figure 10 , showing the input and output interfaces;

[0024] Figure 12 is an exemplary circuit used in a preferred embodiment of the filter module of Figures 10 to 11 ;

[0025] Figure 13 is an image of the interior of an exemplary filter module according to the present disclosure;

[0026] Figure 14A is a schematic of a pedal chain used to generate the spectrum plot of Figure 7 ;

[0027] Figure 14B is a schematic of a pedal chain used to generate the spectrum plot of Figure 8 and Figure 9 ; and

[0028] Figure 15 shows a plurality of representative effect pedals connected in a chain for use with the disclosed filter module. DETAILED DESCRIPTION

[0029] Among the advantages and improvements disclosed herein, other objects and advantages of the disclosed embodiments will become apparent from the following description, in which like numbers represent like parts throughout the several views. Detailed embodiments of the PD filter module and related systems are disclosed; however, it is to be understood that the disclosed embodiments are merely illustrative of the present invention which can be embodied in various forms. Additionally, each example given in connection with the various embodiments of the present invention is intended to be illustrative only and in no way limiting.

[0030] Throughout the specification and claims, unless the context clearly specifies otherwise, the following terms shall have the meaning explicitly associated herein. The phrase “in some embodiments” as used herein does not necessarily refer to the same embodiment, although it may refer to the same embodiment. Similarly, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to different embodiments, although they may refer to different embodiments. Therefore, as described below, various embodiments can be readily combined without departing from the scope or spirit of this application.

[0031] As used herein, “based on” is not exclusive and may be based on additional factors not explicitly described, unless the applicable context clearly specifies otherwise.

[0032] Furthermore, as used herein, the term “or” is equivalent to the term “and / or” unless the context clearly specifies otherwise. The term “based on” is not exclusive but allows for basing on additional factors not described unless the context clearly specifies otherwise. Additionally, throughout the specification, the meanings of “a / an” and “the” include plural references. The meaning of “in” includes both “in” and “on”.

[0033] Furthermore, the terms “substantial,” “substantially,” “similar,” “similarly,” “analogous,” “analogously,” “approximately,” and any combination thereof mean that the difference between the compared features or characteristics is less than 25% of the corresponding value / amplitude of the measured and / or defined features or characteristics being compared.

[0034] First refer to Figures 10-13 This document discloses a PD filter module 10 having an LC filter, an input interface 12, and an output interface 14. This embodiment includes a single output interface 14; however, the innovative concept is not limited thereto. Embodiments have multiple output interfaces for power transmission to multiple loads, whether it be a musical instrument effects pedal (i.e., Figure 15 Component D) or other devices. In the depicted embodiment, input interface 14 is a PD-enabled USB-C interface (3.0 protocol or other protocols) that can receive power from any USB source (including AC or power bank).

[0035] Noise filtering is provided by a two-stage inductor (112) and capacitor (114) filter circuit configured to filter switching power supply noise that may originate from the USB power source. An LC filter circuit included in the PD-enabled filter module 10 is tuned to remove noise from audible frequencies originating from the USB power source. Figure 12 An exemplary circuit 100 used within the disclosed filter module 10 is shown. A preferred embodiment of the filter module 10 shown is configured to transmit 9V power, as most instrument effects pedals currently operate with 9V power. The transmission voltage of the preferred embodiment is not limiting, as other embodiments exist for providing other voltages, such as 12V, 15V, or 18V. Furthermore, embodiments utilizing a programmable power supply (PPS) protocol exist, which allows connected devices to request any voltage in the range of 5-20V, including fractional voltages.

[0036] exist Figure 12 In the illustrated LC circuit, inductor 112 and capacitor 114 cooperate to generate a resonant point, or cutoff frequency, where the impedances of the inductor and capacitor cancel each other out. This allows signals below a predetermined critical frequency to pass through with minimal impedance, while attenuating (filtering out) signals above a predetermined frequency. The circuitry in the depicted preferred embodiment is programmed and tuned specifically for use with a 9V-powered guitar effects pedal; however, this can be adjusted for other end uses. USB-C PD allows the gateway circuitry to request DC voltages from 3.6 to 20V.

[0037] refer to Figure 13 The depicted preferred embodiment includes an LC filter circuit with a relatively large inductor 18 and two capacitors 20, electrically connected downstream of the USB-C connector 22 mounted on the bottom side of the printed circuit board and upstream of the output connector 24. In this embodiment, the filter module 10 includes a 1000uF capacitor 20 and a 330uH inductor, which cooperate in the depicted circuit 100 to effectively filter frequencies lower than those of existing filter modules, approximately 270Hz and above. This eliminates output noise associated with upstream USB power, including low frequencies for which there was no previous solution. Other embodiments exist that are tuned to filter noise at even lower frequencies.

[0038] The effectiveness of the disclosed filter module 10 can be understood by referring to the comparative examples 1-9 described below. Figure 14A and Figure 14B The same effect pedal chain setup is used for each of Examples 7-9, including:

[0039] Guitar Effects Pedal Tuner (120) from D'Addario & Company, Inc.

[0040] Keeley compressor (122)

[0041] Crunch Box (124)

[0042] Boss Super Chorus CH-1 (126)

[0043] Keeley 30ms Dual-Rail Tracker (128)

[0044] For details, please refer to the following: Figure 14B In Examples 8 and 9, different power transmission modules are placed at position A between the power source and the first tread in chain 120. Example 8 uses a similar approach to the reference... Figures 10-13 The innovative PD-supporting filtering module 10, Example 9, employs a commercial converter from Mission Engineering, Inc., which features a USB-C input, supports filtering on the switching side, and offers low-noise performance compared to other products that function as "control modules".

[0045] Example

[0046] Example 1

[0047] Figure 1 This is a noise spectrum diagram of a power supply output with a 20 mA load and no filter module. Figure 14A In addition to the smaller noise peaks throughout, there is a fairly large noise peak at 1500 Hz, measured at approximately 3 mVrms.

[0048] Example 2

[0049] Figure 2 This is the output noise spectrum of the disclosed filter module 10 connected to a power supply with a 20 mA load. All noise peaks have been attenuated, including the large peak at 1500 Hz, which has been attenuated to below 0.1 mVrms (a reduction of at least 30 dB).

[0050] Example 3

[0051] Figure 3 This is a noise spectrum of the output from the aforementioned commercial control module connected to a power supply with a 20 mA load. The spectrum is remarkably similar to that of an unfiltered power supply.

[0052] Example 4

[0053] Figure 4 The graph shows the same setup as Example 1, but with a load of 500mA. There are significant noise peaks, shifted to 2000Hz.

[0054] Example 5

[0055] Figure 5 Is with Figure 2 The same setup is used, but with a load of 500mA. As in Example 2, all noise peaks, including the large peak at 2000Hz, have been attenuated by the disclosed filter module 10.

[0056] Example 6

[0057] Figure 6 The spectrum is the same as in Example 3, but with a load of 500mA. Similarly, the spectrum with the control module appears similar to the spectrum without the filter. Figure 4 ).

[0058] Example 7

[0059] Figure 7 It shows Figure 14A The diagram depicts the output spectrum of the pedal chain, which is powered by the power supply used in the aforementioned example. Among the numerous noise spikes, there is a distinct noise spike of approximately 6 mVrms at 2000 Hz, originating from the power supply. The noise at this frequency is audible.

[0060] Example 8

[0061] Figure 8 It shows Figure 14B The graph depicts the output spectrum of the pedal chain, which has an innovative filter module 10 at position A and is powered by the power supply used in the aforementioned example. The graph shows that the large 2000Hz noise spike has been reduced to approximately 0.1mVrms (approximately 34 dB). At this level, the noise is no longer audible. Other noise spikes have also been reduced.

[0062] Example 9

[0063] at last, Figure 9 It shows Figure 14B The spectrum diagram depicted shows the output of the pedal chain, with the control module located at position A and powered by the power supply from the previous example. Similarly, this spectrum is similar to... Figure 7 (Unfiltered pedal chain). As in Example 7, the noise shown in this spectrum is audible.

[0064] In some embodiments, the filtering module 10 includes circuitry for user and device safety, including switches or other circuitry, to automatically shut off power in the event of output or input polarity reversal, output short circuit, accidental insertion of a 9V power source into the output jack, and / or if the current exceeds 1.5A.

[0065] While a preferred embodiment of the filtering module includes a USB-C connection, this is a non-limiting feature, as other embodiments utilizing USB-A or USB-B connections may exist. Furthermore, this application is not limited to specific data speed protocols, namely USB 1.1, USB 2.0, USB 3.0, and USB 4.0.

[0066] While preferred embodiments have been presented for illustrative purposes, the foregoing description should not be construed as limiting the scope of this application. Therefore, various modifications, adaptations, and substitutions will arise for those skilled in the art without departing from the spirit and scope of this application.

Claims

1. A music effect pedal assembly, comprising: USB PD compatible power supply; At least one music effect pedal electrically connected to the power source; as well as A power transmission and filtering module connected between the power supply and at least one of the music effect pedals; characterized in that: The filtering module includes an input interface supporting USB PD, a power output interface, and an LC circuit between the input interface and the power output interface; The filtering module negotiates power from the power source at a predetermined voltage; and The LC circuit attenuates signals with frequencies higher than a predetermined frequency.

2. The music effect pedal assembly according to claim 1, characterized in that, The predetermined voltage is 9V, and 9V of power is transmitted through the power output interface.

3. The music effect pedal assembly according to claim 2, characterized in that, The input interface is a USB-C interface.

4. The music effect pedal assembly according to claim 1, characterized in that, The input interface is a USB-C interface.

5. The music effect pedal assembly according to claim 4, characterized in that, The LC circuit is configured to attenuate signals with frequencies of approximately 270 Hz and above.

6. The music effect pedal assembly according to claim 5, comprising a plurality of isolated power output interfaces, characterized in that, Each power output interface is configured to transmit an adjustable output voltage, and the output voltages between each power output interface can be different.

7. The music effect pedal assembly according to claim 5, comprising a plurality of isolated power output interfaces, characterized in that, Each power output interface is configured to transmit the same voltage as the others.

8. The music effect pedal assembly according to claim 5, characterized in that, The voltage transmitted through the power output interface is adjustable.

9. The music effect pedal assembly according to claim 1, characterized in that, The input interface that supports USB PD is compatible with the USB 3.0 protocol or a later version.

10. The music effect pedal assembly according to claim 1, characterized in that, The input interface that supports USB PD can operate via the PPS protocol.

11. The music effect pedal assembly according to claim 1, characterized in that, The LC circuit is a two-stage inductor and capacitor filter circuit.

12. The music effect pedal assembly according to claim 1, characterized in that, The LC circuit is configured to attenuate signals with frequencies of approximately 270 Hz and above.

13. The music effect pedal assembly according to claim 1, characterized in that, The at least one music effect pedal, which is electrically connected to the power source, is fixed to a pedal holder.

14. A power transmission and filtering module for low-frequency inductive filtering, comprising: Supports USB PD input interface; A downstream power output interface that supports the USB PD input interface; as well as The LC circuit between the USB PD-supporting input interface and the power output interface is characterized in that the LC circuit is used to attenuate signals with frequencies higher than a predetermined frequency.

15. The power transmission and filtering module according to claim 14, characterized in that, The predetermined voltage is 9V, and 9V of power is transmitted through the power output interface.

16. The power transmission and filtering module according to claim 14, characterized in that, The input interface is a USB-C interface.

17. The power transmission and filtering module according to claim 14, characterized in that, The input interface that supports USB PD is compatible with the USB 3.0 protocol or a later version.

18. The power transmission and filtering module according to claim 14, characterized in that, The LC circuit is a filter circuit consisting of two stages of inductors and capacitors.

19. The power transmission and filtering module according to claim 14, characterized in that, The LC circuit is configured to attenuate signals with frequencies of approximately 270 Hz and above.

20. A music effects pedal assembly, comprising: USB PD compatible power supply; At least one music effect pedal electrically connected to the power source; as well as A power transmission and filtering module connected between the power supply and at least one of the music effect pedals, the filtering module having an input interface supporting USB PD, one or more power output interfaces, and an LC circuit between the input interface and the one or more power output interfaces; characterized in that: The filtering module negotiates power from the power source at a predetermined voltage. The LC circuit attenuates signals with a frequency of approximately 270Hz and above.

Images