Followup: Today I built a version of the TLV4111 circuit with a TCA0372 instead. The TCA0372 can be powered directly by a 9V battery and can drive either a 8 or 16 ohm output coil. The 8 ohm one is almost too strong. The TLV4111 draws about 100 mA from the battery driving an 8 ohm coil, and the TCA0372 also draws about 100 mA driving a 16 ohm coil which is about the same strength as TLV4111 at 8 ohms. That would easily give you 5 hours of play time on a standard 9V. The TLV4111 circuit is only about 50% efficient due to the voltage regulator, whereas the TCA0372 is around 75% efficient. So I'd recommend TCA0372.
Now put a CD4046 after the comparator but before the half-bridge. If you use the standard type-2 phase comparator, you’ll get no phase shift and can set the frequency division with counters. But if you use the type-1 phase comparator, the frequency that it locks to will be more dependant on the VCO, and it will likely lock to harmonics. Putting a potentiometer as the VCO’s resistor will help you control what harmonic it locks onto. Guitar pickups are designed for magnetic reception, less so for actually stimulating the strings. The strings would be better stimulated by an inductor with an iron or ferrite core, as opposed to a rare earth magnet core.
The problem with only one input coil and one output will probably be that such a system tends to favor the strongest resonance. This is how it usually works when you deg a guitar to doo controlled feedback with a loud amp. I'm quite sure that it will tend to just make one string really vibrate nicely and the rest will only have some symphatetic vibrations if the fundamental or the harmonics match up with the string that overpowers the rest. I wish I'm wrong though. It would be cool if it would modulate between the strings like your harmonic mode did between the harmonics of the single string. You could use separate coils and amps for different srings to get chords if nothing else works with multiple strings. Guitar pickups will probably work fine as the input coils as that's what they are built for, but the high impedance will probably make them impossible to drive hard enough with any sensible amplifier. I quess you knew at least most of this already, but anyway... Looking forward to see how thir project will progress.
Other types of coils you can try are from a good sized relay! They are way bigger tho. But magnetics is weird the field is tuned to each application you want a concentrated field acting on the string. A speaker coil is more of a flat field to drive the whole diaphragm. In practice this is done by a double humbucker pickup one side is out other is input and i think you still take the signal out to your speaker.
Yes, they are wound either clockwise or anticlockwise as seen from above. Depending on which way the current flows through, the induced magnetic field will point either up or down through the coil according to some right-hand rule. Normally you wouldn't care, but in this case you do since you want to push (and not pull) on the string as it is moving away.
@@yanikb.1312 The guitar strings are magnetic on account of being magnetized by the magnet. In my next video in this series I show the guitar string being pushed by the coil.
@MichaelKrzyzaniak Someone mentioned using relay coils. I'd suggest trying plunger style solenoid coils such as you find in a copy machine that is used to actuate gates for paper feed and whatnot. Instead of a ring magnet around the outside what if you used a cylindrical rare earth neodymium magnet in the center of the coil? 🤔 Another coil based device I encountered on copy machines is what is called a "magnetic clutch" used to engage a drive shaft with a gear when engaged. They have shorter height coil bobbins than the plunger solenoids. If you have any kind of copier repair shop near you, you might could give them a visit as they will most likely have a boneyard you can source from. Most of the plunger solenoids will be found in the finisher attached to the side of the main machine. Magnetic clutches will be mostly found at the back of the machine where the paper tray feed & transport is located. Several trays powered by a single motor and only when a Magnetic clutch is energized for a particular tray will it then start the paper pickup & feed process.
A 2GHz pentium goes fast enough to easily calculate waveforms like this in real time and still have bandwidth left over to play Tetris. This is what torpedoed the whole electronics hobby. It's good to see someone still into it.
![Fulgorian Harp: [2] Guitar Sustainer Coil Physics](http://i.ytimg.com/vi/vtj1a5HV8LI/mqdefault.jpg)
![Fulgorian Harp: [3] Rewinding guitar pickups and sustaining multiple strings at once](/img/1.gif)
Followup: Today I built a version of the TLV4111 circuit with a TCA0372 instead. The TCA0372 can be powered directly by a 9V battery and can drive either a 8 or 16 ohm output coil. The 8 ohm one is almost too strong. The TLV4111 draws about 100 mA from the battery driving an 8 ohm coil, and the TCA0372 also draws about 100 mA driving a 16 ohm coil which is about the same strength as TLV4111 at 8 ohms. That would easily give you 5 hours of play time on a standard 9V. The TLV4111 circuit is only about 50% efficient due to the voltage regulator, whereas the TCA0372 is around 75% efficient. So I'd recommend TCA0372.
Ah, the sound of gridlocked, rush hour traffic right in my own window you say? And all it costs is tripling my HVAC bill? Where do I sign up?
😂💀👍
I just got a idea to replicate ebow today. This was helpful. Thanks for the awesome video!
Now put a CD4046 after the comparator but before the half-bridge. If you use the standard type-2 phase comparator, you’ll get no phase shift and can set the frequency division with counters. But if you use the type-1 phase comparator, the frequency that it locks to will be more dependant on the VCO, and it will likely lock to harmonics. Putting a potentiometer as the VCO’s resistor will help you control what harmonic it locks onto.
Guitar pickups are designed for magnetic reception, less so for actually stimulating the strings. The strings would be better stimulated by an inductor with an iron or ferrite core, as opposed to a rare earth magnet core.
Great suggestions, thanks for the tips!
Great project!
In my experience with the ebow, changing the position of the exciter coil along the string's length will accentuate certain harmonics.
The problem with only one input coil and one output will probably be that such a system tends to favor the strongest resonance. This is how it usually works when you deg a guitar to doo controlled feedback with a loud amp. I'm quite sure that it will tend to just make one string really vibrate nicely and the rest will only have some symphatetic vibrations if the fundamental or the harmonics match up with the string that overpowers the rest. I wish I'm wrong though. It would be cool if it would modulate between the strings like your harmonic mode did between the harmonics of the single string. You could use separate coils and amps for different srings to get chords if nothing else works with multiple strings.
Guitar pickups will probably work fine as the input coils as that's what they are built for, but the high impedance will probably make them impossible to drive hard enough with any sensible amplifier.
I quess you knew at least most of this already, but anyway... Looking forward to see how thir project will progress.
AAhhhh, the spoiler is that I have already tried it and you are right about all of this! Why didn't you tell me like three months ago 😭
I didn't see a video three months ago. :) I'm sure that if I told you three months ago, you would have tried anyway.
DUDE!! WTF! That SOUNDED AMAZING!!!
God! I need 48 Hours a day pleaze!
My god my stupid ass already stays up for 3 days at a time far too often if there was 48 hours in a day I likely still would and I would die.
reminds me of the hurdy gurdy drone string but with a slight phaser. what a fun instrument!
Other types of coils you can try are from a good sized relay! They are way bigger tho. But magnetics is weird the field is tuned to each application you want a concentrated field acting on the string. A speaker coil is more of a flat field to drive the whole diaphragm. In practice this is done by a double humbucker pickup one side is out other is input and i think you still take the signal out to your speaker.
Day Tripper !
Its always dubious meeting someone who is cleverer than i was.
what happens if you connect the harp strings to electricity?
I will be shaving my buzzers down, to stop the buzzing ! My two heaviest wound strings are terrible for it.
I don understand that schematic
where is the input ? how does it sense strings ?
The sound is generated by the two coils and the string. No need for an in or output jack, the string is both oscillator and "speaker"
Knew there'd be an lm386 in there somewhere 😂
The aeolis harps I heard about were mounted on roofs.
COILS have polarity???
Yes, they are wound either clockwise or anticlockwise as seen from above. Depending on which way the current flows through, the induced magnetic field will point either up or down through the coil according to some right-hand rule. Normally you wouldn't care, but in this case you do since you want to push (and not pull) on the string as it is moving away.
@@MichaelKrzyzaniak You can't push guitar strings using a magnet, not even using an electromagnet. Only pull. Or are guitar strings magnetic?
@@yanikb.1312 The guitar strings are magnetic on account of being magnetized by the magnet. In my next video in this series I show the guitar string being pushed by the coil.
@MichaelKrzyzaniak Someone mentioned using relay coils. I'd suggest trying plunger style solenoid coils such as you find in a copy machine that is used to actuate gates for paper feed and whatnot. Instead of a ring magnet around the outside what if you used a cylindrical rare earth neodymium magnet in the center of the coil? 🤔 Another coil based device I encountered on copy machines is what is called a "magnetic clutch" used to engage a drive shaft with a gear when engaged. They have shorter height coil bobbins than the plunger solenoids. If you have any kind of copier repair shop near you, you might could give them a visit as they will most likely have a boneyard you can source from. Most of the plunger solenoids will be found in the finisher attached to the side of the main machine. Magnetic clutches will be mostly found at the back of the machine where the paper tray feed & transport is located. Several trays powered by a single motor and only when a Magnetic clutch is energized for a particular tray will it then start the paper pickup & feed process.
You have to open two windows
The person who "reverse engineered" that e-bow LM386 schematic made some major mistakes.
Amatuerish. 😑
A 2GHz pentium goes fast enough to easily calculate waveforms like this in real time and still have bandwidth left over to play Tetris. This is what torpedoed the whole electronics hobby. It's good to see someone still into it.
dont use a 5v reg, use a buck