"""
Inductor symbol for JITX Standard Library
This module provides the inductor symbol definition that also
supports the transformer symbol definition.
"""
from __future__ import annotations
import math
from enum import Enum
from dataclasses import dataclass, replace
from jitx.shapes.primitive import Arc, ArcPolyline, Polyline
from jitx.symbol import Direction, Pin
from ..common import DEF_LINE_WIDTH
from ..label import LabelConfigurable, LabelledSymbol
[docs]
class InductorCoreStyle(Enum):
"""Inductor core styles"""
NO_CORE = "no_core"
SINGLE_BAR_CORE = "single_bar_core"
DOUBLE_BAR_CORE = "double_bar_core"
# Inductor constants
DEF_IND_PITCH = 4.0
DEF_IND_CORE_STYLE = InductorCoreStyle.NO_CORE
DEF_IND_PORCH_WIDTH = 0.25
DEF_IND_PERIODS = 3
[docs]
@dataclass
class InductorConfig(LabelConfigurable):
"""
Configuration for inductor symbols
Defines the geometric and visual parameters for inductor symbols.
"""
pitch: float = DEF_IND_PITCH
"""Distance between pin points"""
polarized: bool = False
"""Whether the inductor has polarity"""
core_style: InductorCoreStyle = DEF_IND_CORE_STYLE
"""Style of the inductor core"""
porch_width: float = DEF_IND_PORCH_WIDTH
"""Length of straight sections at ends"""
periods: int = DEF_IND_PERIODS
"""Number of half-circles in the inductor winding shape"""
line_width: float = DEF_LINE_WIDTH
"""Width of the inductor lines"""
[docs]
class InductorSymbol(LabelledSymbol):
"""Inductor symbol with graphics and pins."""
config: InductorConfig
inductor_bars: tuple[()] | tuple[Polyline] | tuple[Polyline, Polyline]
inductor_coils: ArcPolyline
inductor_porches: tuple[Polyline, Polyline]
def __init__(
self,
config: InductorConfig | None = None,
partial_symbol: bool = False,
**kwargs,
):
"""
Initialize inductor symbol
Args:
config: Config object, or None to use defaults
partial_symbol: Whether to build a partial symbol (no pins or labels)
**kwargs: Individual parameters to override defaults
"""
from ..context import SymbolStyleContext
context = SymbolStyleContext.get()
if config is None:
if context is None:
config = InductorConfig()
else:
config = context.inductor_config
self.config = replace(config, **kwargs)
self._build_artwork()
# Skip pins and labels if requested:
if not partial_symbol:
self._build_pins()
self._build_labels(ref=Direction.Right, value=Direction.Right)
def _build_artwork(self) -> None:
"""Build the coil glyphs for an inductor based on inductors.stanza."""
w = math.floor(self.pitch / 2)
if self.porch_width > w:
raise ValueError(
f"Inductor porch width {self.porch_width} cannot be greater than half the pitch rounded down ({w} = math.floor({self.pitch}/2))"
)
circ_start = w - self.porch_width
circ_len = 2 * circ_start
diameter = circ_len / self.periods
radius = diameter / 2.0
# Front and back porches
self.inductor_porches = (
Polyline(self.line_width, [(0, -circ_start), (0, -w)]),
Polyline(self.line_width, [(0, w), (0, circ_start)]),
)
# Coils (series of semi-circles)
arcs = []
for i in range(self.periods):
center_y = circ_start - radius - (i * diameter)
arcs.append(Arc((0, center_y), radius, 90.0, 180.0))
self.inductor_coils = ArcPolyline(self.line_width, arcs)
# Core bars
line_margin = 3 * self.line_width
core_x = -(radius + line_margin)
if self.config.core_style == InductorCoreStyle.SINGLE_BAR_CORE:
self.inductor_bars = (
Polyline(
self.line_width, [(core_x, circ_start), (core_x, -circ_start)]
),
)
elif self.config.core_style == InductorCoreStyle.DOUBLE_BAR_CORE:
self.inductor_bars = (
Polyline(
self.line_width, [(core_x, circ_start), (core_x, -circ_start)]
),
Polyline(
self.line_width,
[
(core_x - line_margin, circ_start),
(core_x - line_margin, -circ_start),
],
),
)
def _build_pins(self):
"""
Build symbol pins for the inductor
Creates appropriate pins based on polarity setting.
Polarized inductors get 'a' (anode) and 'c' (cathode) pins,
Non-polarized inductors get generic 'p[1]' and 'p[2]' pins.
"""
w = math.floor(self.pitch / 2)
if self.polarized:
self.a = Pin(at=(0, w), direction=Direction.Up)
self.c = Pin(at=(0, -w), direction=Direction.Down)
else:
self.p = [
None, # Having an empty entry increments pin index.
Pin(at=(0, w), direction=Direction.Up),
Pin(at=(0, -w), direction=Direction.Down),
]
# Convenience properties to access config values
@property
def pitch(self) -> float:
"""See :attr:`~.InductorConfig.pitch`."""
return self.config.pitch
@property
def polarized(self) -> bool:
"""See :attr:`~.InductorConfig.polarized`."""
return self.config.polarized
@property
def porch_width(self) -> float:
"""See :attr:`~.InductorConfig.porch_width`."""
return self.config.porch_width
@property
def periods(self) -> int:
"""See :attr:`~.InductorConfig.periods`."""
return self.config.periods
@property
def line_width(self) -> float:
"""See :attr:`~.InductorConfig.line_width`."""
return self.config.line_width
@property
def label_config(self) -> LabelConfigurable:
"""Configuration object that provides label configuration"""
return self.config
