- #1
ulfurh
- 5
- 1
Hello everyone,
For the past 4 years I have been working on a new type of musical instrument that fuses together elements from electronic music into the acoustic realm.
The instrument consists of 26 strings inside a wooden enclosure that are actuated (or "bowed") by the use of electromagnets. Each string driver circuit is turned on by touching the capacitive sensor pads on the front. The latest iteration looks like this :
It's a very exciting project, as the timbre and playability is unlike anything else out there... However, there is still a lot of room for improvements, and the most important factor at this point is the design of the electromagnets that make the strings vibrate.
I am currently using coils with E-shaped cores of 8.9 DC resistance, they are 21mm in length and 20mm in diameter. They are positioned about one centimeter away from the string, and sometimes I put a small neo-dymium magnet on the end of the core to increase the effect on the string.
I believe the relatively powerful magnetic flux I am currently generating with my string-driver coils is mostly being wasted outside of the general string area in a typical figure eight shaped field. I would really like to try and concentrate the coil energy more towards just the string itself - this would hopefully allow me to get away with a smaller amp design.
I have tried running current through the string placing a neo-dymium magnet close to it - but the electromagnet solution seems to work a lot better.
The size of the electromagnets is a major consideration, but I'm very interested in learning more about for instance the effect of diameter vs length of a coil on the flux shape - and also the use of permalloys/mu-metals to concentrate magnetic fields onto a specific target (the string!).
Also, maybe there are other core configurations worth considering - U-shaped cores for instance - but finding vendors for such electromagnets is very difficult online - making it difficult to prototype...
Furthermore, I'm very interested in learning more about the difference between current and voltage when it comes to generating magnetic fields. Is it true that a current source amplifier is better suited to generating flux than a voltage source amp? (this may be better suited to the engineering forum!)
I am by no means literate in physics, or even math - however I am very persistent, and know a thing or two about audio circuitry... I'd really appreciate your thoughts on the matter, any thoughts at all!
All the best,
-ulfurh
For the past 4 years I have been working on a new type of musical instrument that fuses together elements from electronic music into the acoustic realm.
The instrument consists of 26 strings inside a wooden enclosure that are actuated (or "bowed") by the use of electromagnets. Each string driver circuit is turned on by touching the capacitive sensor pads on the front. The latest iteration looks like this :
It's a very exciting project, as the timbre and playability is unlike anything else out there... However, there is still a lot of room for improvements, and the most important factor at this point is the design of the electromagnets that make the strings vibrate.
I am currently using coils with E-shaped cores of 8.9 DC resistance, they are 21mm in length and 20mm in diameter. They are positioned about one centimeter away from the string, and sometimes I put a small neo-dymium magnet on the end of the core to increase the effect on the string.
I believe the relatively powerful magnetic flux I am currently generating with my string-driver coils is mostly being wasted outside of the general string area in a typical figure eight shaped field. I would really like to try and concentrate the coil energy more towards just the string itself - this would hopefully allow me to get away with a smaller amp design.
I have tried running current through the string placing a neo-dymium magnet close to it - but the electromagnet solution seems to work a lot better.
The size of the electromagnets is a major consideration, but I'm very interested in learning more about for instance the effect of diameter vs length of a coil on the flux shape - and also the use of permalloys/mu-metals to concentrate magnetic fields onto a specific target (the string!).
Also, maybe there are other core configurations worth considering - U-shaped cores for instance - but finding vendors for such electromagnets is very difficult online - making it difficult to prototype...
Furthermore, I'm very interested in learning more about the difference between current and voltage when it comes to generating magnetic fields. Is it true that a current source amplifier is better suited to generating flux than a voltage source amp? (this may be better suited to the engineering forum!)
I am by no means literate in physics, or even math - however I am very persistent, and know a thing or two about audio circuitry... I'd really appreciate your thoughts on the matter, any thoughts at all!
All the best,
-ulfurh