README
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Single (2-layer) bifilar coil
This is a design of a bifilar coil, meaning that when this design is fabricated on a two-layer printed circuit board (PCB), there will be a single bifilar coil.
This designs differs from the others in that a single coil is devoted to one layer and the board itself is the dielectric between the top and bottom coils.
This design requires that an external wire connect the inner terminal of one coil to the outer terminal of the other coil (with the added benefit of being able to insert a tuning capacitor in between the two coils.)
The theory is that when you drive the coil with a sine wave at its resonant frequency, it can transfer power at its greatest efficiency.
The beauty of this design is that it is parametric.
How it is wired
Both coils are concentric and wind in the same direction. Therefore the magnetic field from each coil section combines uniformly with the other coil resulting in a stronger, cohesive field.
Additionally, this design differs in that the two coils are directly sandwiched together via the board's dielectric such that the capacitance is stronger between the coils.
This shows the various layers on a small (100mm x 100mm) coil to highlight the wiring and various layers of the PCB:
Parametric design
In this design, coils can be created with varying board size, trace widths, and gaps between traces. As a result, this parametric design could theoretically be used for coils of any manufacturable size (from microscopic on up).
Example coils
In this section, we will document emperically-measured resistances and resonant frequencies of fabricated coils as they become available.
Coil 1
Here is a large (400mm x 400mm) PCB with 92 windings per coil:
Please visit Master Ivo's YouTube channel to see some novel uses of bifilar coils.
Enjoy!
License
Copyright 2019 Glenn M. Lewis. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Documentation
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Overview ¶
bifilar-with-capacitor creates Gerber files (and a bundled ZIP) representing a bifilar coil (https://en.wikipedia.org/wiki/Bifilar_coil) with the ability to connect the two windings with a capacitor (or not) for manufacture on a printed circuit board (PCB).
This designs differs from the others in that a single coil is devoted to one layer and the board itself is the dielectric between the top and bottom coils.
This design requires that an external wire connect the inner terminal of one coil to the outer terminal of the other coil (with the added benefit of being able to insert a tuning capacitor in between the two coils.)
Copyright 2019 Glenn M. Lewis. All Rights Reserved.
Source Files