Flat Air Core Inductor Coil, 289 Turns of 0.16 mm Enameled Copper Wire, 20.2 x 12.6 x 3.5 mm, Hollow Rectangular Winding
A flat air core inductor coil: 289 turns of 0.16 mm enameled copper wire wound into a hollow rectangle, 3.5 mm thick, with the ends stripped and tinned. Nothing sits in the window, so the winding geometry is the electrical specification, and the part is made to size, turn count and wire on request.
- Air core, hollow rectangular winding, no core material in the window
- 289 turns of 0.16 mm high-purity enameled copper wire
- Tight layer winding, stacked to a 3.5 mm thickness
- Outer 20.2 mm by 12.6 mm, window 15.6 mm by 7.36 mm
- Leads 20 mm long, stripped and tinned
- Stated as high Q factor with low magnetic loss
- Custom size, winding and wire configuration
1. Product Name
A flat air core inductor coil, wound as a hollow rectangle. 289 turns of 0.16 mm high-purity enameled copper wire are laid in tight layers to build a flat winding 3.5 mm thick, and the two ends are stripped and tinned for soldering. The envelope is 20.2 mm by 12.6 mm, the window is 15.6 mm by 7.36 mm, and the leads are 20 mm long. Size, winding and wire configuration are made to order.
What the numbers mean here. On a cored part the core sets the inductance and the winding trims it. This winding has nothing in the window, so the inductance is set by the geometry: the outer and inner dimensions, the turn count and the wire diameter quoted on this page are the electrical specification, not just a mechanical one. If a specific inductance is required, it has to be asked for against a frequency, because the supplied material does not state one.
2. Construction & Materials
The winding. 0.16 mm enameled copper, 289 turns, tight layer winding. The layers are stacked flat rather than piled into a round bundle, which is what produces a 3.5 mm thickness against a 20.2 mm length. A tape band holds the winding at the point where the leads leave, and the lead ends are stripped and tinned so they can be soldered without preparation.
The profile. Seen edge-on the part is a stack of winding layers, not a body with a lid: there is no case, no bobbin flange and no potting. That is the point of the format where height is the constraint, and it is also why the thickness tolerance is given as 0.5 mm rather than as a machined dimension.
The dimensions. Every dimension on this part is quoted with a tolerance, which is unusual enough to be worth reading carefully: outer length 20.2 mm and outer width 12.6 mm to within 1 mm, thickness 3.5 mm to within 0.5 mm, window 15.6 mm by 7.36 mm to within 0.5 mm, and leads 20 mm to within 2 mm. A coil is a wound part, so the winding itself moves; the tolerances are what the supplier is prepared to hold.
3. Feature
Air core, hollow rectangular winding. No core, no bobbin and no potting in the window, so the inductance comes from the winding geometry.
289 turns of 0.16 mm enameled copper wire. High-purity enameled copper, stated on the detail render with the turn count.
Tight layer winding. The layers are laid flat and tight, which is what holds the 3.5 mm thickness across a 20.2 mm length.
Precision stripped and tinned terminals. Both lead ends are stripped and tinned, so they go straight into a solder joint or a terminal block.
20 mm leads. Long enough to reach a pad or a connector without an extension, and quoted to within 2 mm.
Stated as high Q factor with low magnetic loss. The sheet's own description of the magnetic behaviour; no Q figure is quoted.
Fast energy transfer, low loss, high efficiency. The application the sheet names for the part, rather than a measured efficiency.
Custom size, winding and wire configuration. The geometry is the specification, so a different window, turn count or wire is a different drawing.
4. Advantage
Nothing in the magnetic path. An air core has no core material to add loss or to saturate, which is why the winding geometry carries the specification.
Reproducible from the sheet. Turn count and wire diameter are stated, so a replacement or a scaled version can be specified without a sample in hand.
Flat where height is the constraint. 3.5 mm thick against a 20.2 mm length: it fits where a pot core or a toroid will not.
Solderable as supplied. Stripped and tinned ends remove the preparation step at the bench.
Made to the drawing. Size, winding and wire are all offered as custom, from the same flat-wound geometry.
5. Application
Wireless power transfer. Charging pads and receiver coils, the application the sheet leads with.
Smart sensing. Where the coil itself is the sensing element rather than a component in a filter.
RFID and signal transmission. The high-frequency, low-loss use the sheet names for this winding.
Precision SMT modules. Thin wound parts that go onto a populated board rather than into a magnetics can.
6. Specifications
The tables below reproduce what the supplied material states for this coil. Where no figure is given, the cell says so instead of carrying a number in from another winding. Note that the electrical side of an inductor is largely absent from the source: inductance, resistance, Q and current are not stated.
6.1 Summary
| Item | Specification | Note |
|---|---|---|
| Product type | Flat air core inductor coil | Coil structure: flat wound, hollow |
| Core | Air core | No core material in the window |
| Winding material | Enameled copper wire | High purity, 0.16 mm |
| Number of turns | 289 | Tight layer winding |
| Outer size | 20.2 x 12.6 mm | Both within 1 mm |
| Thickness | 3.5 mm | Within 0.5 mm |
| Window | 15.6 x 7.36 mm | Within 0.5 mm |
| Leads | 20 mm, stripped and tinned | Within 2 mm |
| Customization | Size, winding, wire configuration | Made to drawing |
| Inductance | Not stated | Ask for it at a stated frequency |
| DC resistance | Not stated | Ask for it with the inductance |
| Q factor | Described as high | No figure quoted |
| Model number | None assigned | Ordered by drawing or description |
6.2 Winding and electrical
| Parameter | Value | Note |
|---|---|---|
| Wire diameter | 0.16 mm | Enameled copper, high purity |
| Turn count | 289 turns | Tight layer winding |
| Winding form | Flat, hollow rectangle | Layers stacked through the thickness |
| Termination | Stripped and tinned | Both lead ends |
| Lead length | 20 mm | Within 2 mm |
| Inductance | Not stated | Not measured or not supplied |
| DC resistance | Not stated | Not measured or not supplied |
| Q value and current rating | Not stated | Q described as high only |
6.3 Mechanical dimensions
| Item | Value | Tolerance / note |
|---|---|---|
| Outer length | 20.2 mm | Within 1 mm |
| Outer width | 12.6 mm | Within 1 mm |
| Thickness | 3.5 mm | Within 0.5 mm, stack of winding layers |
| Inner length | 15.6 mm | Within 0.5 mm |
| Inner width | 7.36 mm | Within 0.5 mm |
| Lead length | 20 mm | Within 2 mm, from the winding |
| Lead spacing at exit | Not stated | Check on the drawing |
| Weight | Not stated | Check on the drawing |
6.4 Materials
| Item | Specification | Note |
|---|---|---|
| Conductor | Enameled copper wire | 0.16 mm, high purity |
| Core | None | Air core, hollow window |
| Insulation | Enamel coating on the wire | Grade not stated |
| Winding retention | Tape band at the lead exit | Visible on the renders |
| Terminal finish | Tinned | Stripped before tinning |
| Encapsulation | None | Open winding, no potting |
6.5 Quality and inspection
| Item | Statement | Note |
|---|---|---|
| Inspection | 100 % full inspection | Stated for the production run |
| Quality control | Strict quality control | Stated, method not given |
| Safety and reliability | High standards claimed | No standard named |
| Electrical test data | Not supplied | No L, DCR or Q figure |
| Certificate number | Not supplied | No test report with the material |
7. Ordering
There is no model number on this build, so the part is ordered by description or by drawing: flat air core coil, 289 turns, 0.16 mm enameled copper wire, 20.2 mm by 12.6 mm, 3.5 mm thick, 20 mm tinned leads. Size, winding and wire configuration are all offered as custom, so a different turn count, a different wire diameter or a different window is a new drawing rather than a variant of this one. If the circuit needs a stated inductance or a DC resistance, quote it with the measurement frequency when enquiring.
Certification: no certificate or test report was supplied with this material, so no compliance claim is made on this page and the render that carries a row of certification badges was not used. If the listing needs a certificate, quote the number from the certificate itself.
Brand / manufacturer: ZXY, Shenzhen Zhixiangyuan Electronics Co., Ltd. http://www.zxycoil.com