Electromagnetic pickup for stringed musical instrument, and an electric guitar

• US 7,994,413 B2
• Filed: 10/16/2009
• Issued: 08/09/2011
• Est. Priority Date: 10/17/2008
• Status: Expired due to Fees

• Current Assignee: Jarno Johannes Salo
• Original Assignee: Jarno Johannes Salo
• Inventors: Salo, Jarno Johannes
• Primary Examiner(s): Donels; Jeffrey
• Assistant Examiner(s): Millikin; Andrew R
• Application Number:
  US12/580,884
• Publication Number:
  US 20100122623A1
• Time in Patent Office: 662 Days
• Field of Search: 84726-728
• US Class Current: 84/726
• CPC Class Codes: G10H 2220/515 Staggered, i.e. two coils side by side
• CPC Class Codes: G10H 3/181 Details of pick-up assemblies

Abstract

An electromagnetic pickup for a musical instrument, has two coils (2, 3) with pole pieces (4-8, 9-13) in their core regions and a connection that connects the two coils together, out of phase, in series or in parallel, so that they cancel each others extraneous noise and hum. To accomplish a noise-free pickup with the clarity and dynamics of a single coil pickup, and a uniform output level throughout its longitudinal axis, the coils are partly overlapping each other, the pole pieces in the core region of the first coil are partly overlapping with the pole pieces in the core region of the second coil, and the coils (2, 3) with the pole pieces (6-8, 1-13) induce the same voltage in the overlapping area (14) as the voltage induced by the coils and the pole pieces in their core regions outside the overlapping area (14).

Claims

1. An electromagnetic pickup for a stringed musical instrument having a longitudinal first coil (2, 2′

) having a first end (15, 15′

) and a second end (16, 16′

) and a second longitudinal coil (3, 3′

) having a first end (17, 17′

) and a second end (18, 18′

), both coils having a core region made of at least one permanent magnet or magnetically permeable material (4-8 and 9-13, 48′ and

913′

), and the said first coil core region (4-8, 48′

) has a magnetic polarity opposite to the said second coil core region (9-13, 913′

), and a connection that connects the said two coils (2, 3, 2′

, 3′

) out of phase with one another, either in series or in parallel, so that any extraneous noise or hum is cancelled, characterized by the overlapping area (14) in which the two coils (2, 3, 2′

, 3′

) are partly overlapping each other and the core region (4-8, 48′

) of the said first coil (2, 2′

) is partly overlapping with the core region (9-13, 913′

) of the said second coil (3, 3′

), and by that the coils (2, 2′

, 3, 3′

) having the core regions (4-13, 48′

, 913′

) are set to induce the same voltage in the overlapping area (14) that the coils (2, 2′

, 3, 3′

) induce outside the overlapping area (14).

2. An electromagnetic pickup of claim 1, wherein the first end (15) of the first coil (2, 2′

) has fewer turns of coil than the number of turns of coil in the area (19) that is outside the overlapping area (14).

3. An electromagnetic pickup of claim 2, wherein the first end (17) of the second coil (3, 3′

) has fewer turns of coil in the overlapping area (14) than the number of turns of coil in the area (20) that is outside the overlapping area (14).

4. An electromagnetic pickup of claim 3, wherein the said first coil (2, 2′

) and the said second coil (3, 3′

) have approximately the same number of turns in the overlapping area (14).

5. An electromagnetic pickup of claim 1, wherein the coils (2, 3, 2′

, 3′

) are decreasing in width in the overlapping area (14) and wherein the width (d) of the coils (2, 3, 2′

, 3′

) is generally smaller in the overlapping area (14) than the width (D) in the areas (19, 20) outside the overlapping area (14).

6. An electromagnetic pickup of claim 5, wherein the width (d) of the pole pieces in the core regions (4-13. 48, 913) of the coils (2, 2′

, 3, 3′

) is smaller in the overlapping area (14) than the width (D) outside the overlapping area (19, 20).

7. An electromagnetic pickup of claim 6, wherein both coils (2;

3) have a first core region (7, 8;

12, 13) in the overlapping area (14) and a secondary core region (4-6;

9-11) outside the overlapping area (14).

8. An electromagnetic pickup of claim 7, wherein the first pole pieces in the first core regions (7, 8;

12, 13) are surrounded by 1000-5000 turns of coil wire, and the said second pole pieces of the second core region are surrounded by 6000-12000 turns of coil wire.

9. An electromagnetic pickup of claim 8 wherein the pole pieces in the core regions (4-8, 9-13) of coils (2, 3) are permanent magnets.

10. An electromagnetic pickup of claim 7, wherein the first pole pieces in the first core region (7;

12) are surrounded by 1000-3000 turns of coil wire, and the said second pole pieces of the said second core region (4-6;

9-11) are surrounded by 7000-11 000 turns of coil wire.

11. An electromagnetic pickup of claim 10 wherein the pole pieces in the core regions (4-8, 9-13) of coils (2, 3) are permanent magnets.

12. An electromagnetic pickup of claim 7 wherein the pole pieces in the core regions (4-8, 9-13) of coils (2, 3) are permanent magnets.

13. An electromagnetic pickup of claim 12 wherein the core regions (4-6;

9-11) consist of three permanent magnets set in line, the distance between each of the three magnets in the said line being equal.

14. An electromagnetic pickup of claim 1, wherein the longitudinal axis (Z-Z) of coils (2, 3) is set in an angle •

=5-20 degrees as compared to the longitudinal axis of the pickup.

15. An electromagnetic pickup of claim 1, wherein the overall width (W) of the pickup is 20 mm or less and the length (S) of the pickup is 80 mm or less.

16. An electric guitar having a pickup with a first longitudinal coil (2, 2′

) having a first end (15, 15′

) and a second end (16, 16′

), and a second longitudinal coil (3, 3′

) having a first end (17, 17′

) and a second end (18, 18′

), where both coils (2, 3, 2′

, 3′

) have pole pieces (4-8 and 9-13, 48 and 913) in their core region made of magnetically permeable material, and the said first pole pieces (4-8, 48′

) of the said first core region have an opposite magnetic polarity compared to the said second pole pieces (9-13;

913) in the said second core region, and a connection that connects the two coils (2, 2′

, 3, 3′

) to one another out of phase either in parallel or in series, so that they cancel each other'"'"'s extraneous noise and hum, characterized by the area (14) where the coils (2, 3, 2′

, 3′

) are partly overlapping each other and the first pole pieces (4-8, 48) in the core region of the first coil (2, 2′

) are partly overlapping the pole pieces (9-13, 913′

) in the core region of the second coil (3, 3′

), and by that in the overlapping area (14), the coils (2, 3, 2′

, 3′

) with the pole pieces (4-13, 48′

, 913′

) in their core regions induce a voltage of the same level that is induced by the coils (2, 3, 2′

, 3′

) with the pole pieces (4-13, 48′

, 913′

) in their core regions outside the overlapping area (14).

17. An electric guitar of claim 16, wherein the number of turns of the coil is smaller in the first end (15) of the first coil (2) in the overlapping area (14) than the number of turns of the coil in the second end (19) of the first coil (2) outside the overlapping area (14), wherein the number of turns of the coil is smaller in the first end (17) of the second coil (3) in the overlapping area (14) than the number of turns of the coil in the second end (20) of the second coil (3) outside the overlapping area (14), and wherein the number of turns of the coil in the first coil (2) in the overlapping area (14) is the same, or in the same region, as the number of turns of the coil in the second coil (3) in the overlapping area (14).

18. An electric guitar of claim 17, wherein both coils (2;

3) have a first core region (7;

12) placed in the overlapping area (14) and a second core region (4-6;

9-11) placed outside the overlapping area (14), and the said first core regions (7;

12) are both surrounded by 1000-5000 turns of coil wire, and the said second core regions (4-6;

9-11) are both surrounded by 6000-12000 turns of coil wire.

19. An electric guitar of claim 16, wherein both coils (2;

3) have a first core region (7;

12) placed in the overlapping area (14) and a second core region (4-6;

9-11) placed outside the overlapping area (14), and the said first core regions (7;

12) are both surrounded by 1000-5000 turns of coil wire, and the said second core regions (4-6;

9-11) are both surrounded by 6000-12000 turns of coil wire.