Basic Elements¶

See Electrical Elements for complete class definitions for these elements.

Two-terminal¶

Two-terminal devices subclass schemdraw.elements.Element2Term, and have leads that will be extended to make the element the desired length depending on the arguments. All two-terminal elements define start, end, and center anchors for placing, and a few define other anchors as shown in blue in the tables below. Some elements have optional parameters, shown in parenthesis in the table below.

Resistors¶

Resistors elements change style based on IEEE/U.S. vs IEC/European style configured by schemdraw.elements.style(). Selectable elements, such as Resistor, point to either ResistorIEEE or ResistorIEC, for example.

IEEE Style¶

IEEE style, common in the U.S., is the default, or it can be configured using

elm.style(elm.STYLE_IEEE)

Resistor

ResistorVar

Potentiometer

Photoresistor

Fuse

IEC/European Style¶

IEC style can be enabled using

elm.style(elm.STYLE_IEC)

Resistor

ResistorVar

Potentiometer

Photoresistor

Fuse

All Resistors¶

Either IEEE or IEC styles are always available with these Elements.

ResistorIEEE

ResistorIEC

ResistorVarIEEE

ResistorVarIEC

PotentiometerIEEE

PotentiometerIEC

PhotoresistorIEEE

PhotoresistorIEC

FuseUS

FuseIEEE

FuseIEC

Rshunt

Capacitors and Inductors¶

Inductors have anchors intended for easy positioning of a mutual inductance dot near the element.

Capacitor

Capacitor(polar=True)

Capacitor2

Capacitor2(polar=True)

CapacitorVar

CapacitorTrim

Inductor

Inductor(core=True)

Inductor2

Inductor2(loops=2)

Diodes¶

All diodes may be filled by passing fill=True.

Diode

Diode(fill=True)

Schottky

DiodeTunnel

DiodeShockley

Zener

DiodeTVS

Varactor

LED

LED2

LED(fill=’red’)

Photodiode

Diac

Triac

SCR

Miscellaneous¶

Breaker

Crystal

CPE

Josephson

Josephson(box=True)

Motor

Lamp

Lamp2

Neon

Thermistor

Memristor

Memristor2

Jack

Plug

Terminal

SparkGap

Nullator

Norator

CurrentMirror

VoltageMirror

Sources and Meters¶

Source

SourceV

SourceI

SourceSin

SourcePulse

SourceSquare

SourceTriangle

SourceRamp

SourceControlled

SourceControlledI

SourceControlledV

BatteryCell

Battery

BatteryDouble

Solar

MeterV

MeterA

MeterI

MeterOhm

MeterArrow

Box-Style Meters¶

MeterAnalog

MeterDigital

Oscilloscope

The “Box” style meters have many configuration options. See class definitions for more details. Some examples are shown below.

with schemdraw.Drawing() as d:
    elm.MeterAnalog(needle_percent=30)
    d.move(2)
    elm.MeterAnalog(window_fill='skyblue', input_fill='black').anchor('in1')
    d.move(2)
    elm.MeterAnalog().label('V', loc='name').label('–', loc='in1', fontsize=10).label('+', loc='in2', fontsize=10).anchor('in1')
    d.move(2)
    elm.MeterDigital().label('10 V', loc='display', color='red', fontsize=14).anchor('in1')
    elm.Oscilloscope(signal='sine').at((0, -2))
    d.move(2)
    elm.Oscilloscope(signal='square').anchor('in1')
    d.move(2)
    elm.Oscilloscope(signal='triangle', signal_color='blue').anchor('in1')
    d.move(2)
    elm.Oscilloscope(signal='sine', signal_lw=1, grid=False).anchor('in1')

Switches¶

Button

Button(nc=True)

Button(contacts=False)

Switch

Switch(nc=True)

Switch(action=’open’)

Switch(action=’close’)

Switch(contacts=False)

Switch(contacts=False, nc=True)

SwitchReed

Lines and Arrows¶

Line

Arrow

Arrow(double=True)

DataBusLine

Also see Connecting Elements.

Single-Terminal¶

Single terminal elements are drawn about a single point, and do not move the current drawing position.

Power and Ground¶

Ground

GroundSignal

GroundChassis

Vss

Vdd

Antennas¶

Antenna

AntennaLoop

AntennaLoop2

Connection Dots¶

Dot

Dot(open=True)

DotDotDot

Arrowhead

NoConnect

Switches¶

The standard toggle switch is listed with other two-terminal elements above. Other switch configurations are shown here.

Single-pole double-throw¶

Two options for SPDT switches can be also be drawn with arrows by adding action=’open’ or action=’close’ parameters.

SwitchSpdt

SwitchSpdt2

SwitchSpdt(action=’open’)

SwitchSpdt2(action=’open’)

SwitchSpdt(action=’close’)

SwitchSpdt2(action=’close’)

Double-pole¶

DPST and DPDT switches have a link parameter for disabling the dotted line lnking the poles.

SwitchDpst

SwitchDpdt

SwitchDpst(link=False)

SwitchDpdt(link=False)

Rotary Switch¶

The rotary switch schemdraw.elements.switches.SwitchRotary takes several parameters, with n being the number of contacts and other parameters defining the contact placement.

SwitchRotary(n=6)

DIP Switch¶

A set of switches in a dual-inline package, where can show each switch flipped up or down. See schemdraw.elements.switches.SwitchDIP for options.

SwitchDIP

SwitchDIP(pattern=[0, 0, 1])

Audio Elements¶

Speakers, Microphones, Jacks

Speaker

Mic

AudioJack

AudioJack(ring=True)

AudioJack(switch=True)

AudioJack(switch=True, ring=True, ringswitch=True)

Labels¶

The Label element can be used to add a label anywhere. The Gap is like an “invisible” element, useful for marking the voltage between output terminals.

Gap(label=[‘+’, ‘Gap’, ‘-‘])

Label(label=’Hello’)

Tag(label=’Tag’)

Operational Amplifiers¶

The schemdraw.elements.opamp.Opamp element defines several anchors for various inputs, including voltage supplies and offset nulls. Optional leads can be added using the leads parameter, with anchors exteded to the ends of the leads.

Opamp

Opamp(sign=False)

Opamp(leads=True)

Transistors¶

Bipolar Junction Transistors¶

Bjt

BjtNpn

BjtPnp

Bjt(circle=True)

BjtNpn(circle=True)

BjtPnp(circle=True)

BjtPnp2c

BjtPnp2c(circle=True)

NpnSchottky

PnpSchottky

IgbtN

IgbtP

NpnPhoto

PnpPhoto

Field-Effect Transistors¶

NFet

PFet

NFet(bulk=True)

PFet(bulk=True)

JFet

JFetN

JFetP

JFetN(circle=True)

JFetP(circle=True)

Hemt

Hemt(split=False)

Hemt(arrow=False)

NMos

PMos

NMos(diode=True)

PMos(diode=True)

NMos(circle=True)

PMos(circle=True)

AnalogNFet

AnalogPFet

AnalogBiasedFet

AnalogNFet(bulk=True)

AnalogPFet(bulk=True)

AnalogBiasedFet(bluk=True)

AnalogBiasedFet(arrow=False)

AnalogPFet(arrow=False)

AnalogBiasedFet(arrow=False)

AnalogNFet(offset_gate=False)

AnalogPFet(offset_gate=False)

AnalogBiasedFet(offset_gate=False)

“Two-Terminal” Transistors¶

Another set of transistor elements subclass schemdraw.elements.Element2Term so they have emitter and collector (or source and drain) leads extended to the desired length. These can be easier to place centered between endpoints, for example.

BjtNpn2

BjtPnp2

BjtPnp2c2

NFet2

PFet2

JFetN2

JFetP2

NMos2(diode=True)

PMos2(diode=True)

NMos2(circle=True)

PMos2(circle=True)

Vacuum Tubes¶

A generic configurable vacuum tube is provided in schemdraw.elements.tubes.VacuumTube. It may be created with any number of grids, an indirectly-heated or cold cathode, multiple anode options, and an optional heater filament. Some options are below.

with schemdraw.Drawing():
    elm.VacuumTube(cathode='cold', anodetype='narrow', grids=0, heater=False)
    elm.VacuumTube(cathode='none', heater=True).at((3, 0))
    elm.VacuumTube(anodetype='dot', grids=2).at((6, 0))
    elm.VacuumTube(grids=8).at((9, 0))

For the basic tube, anchors are anode, cathode, cathode_R (the right-hand connection to the cathode), grid, grid_R, and heater anchors heat1 and heat2. When multiple grids are present, the grid anchors are grid_N and grid_NR where N is the grid number from the top down.

Common vacuum tubes are defined from the base VacuumTube element.

The triode, tetrode, and pentode include anchors named for function: control, screen, and suppressor. The pentode includes a strap parameter to connect the suppressor to the cathode.

with schemdraw.Drawing():
    elm.TubeDiode().label('TubeDiode')
    elm.Triode().at((3, 0)).label('Triode')
    elm.Tetrode().at((6, 0)).label('Tetrode')
    elm.Pentode().at((9, 0)).label('Pentode')
    elm.Pentode(strap=True).at((12.5, 0)).label('Pentode(strap=True)')

The anchors are positioned internal to the tube envelope to allow connection from either side. Connecting lines extend into the envelope, and pin numbers appear just outside.

with schemdraw.Drawing():
    tube = (elm.Pentode()
               .label('1', 'cathode')
               .label('2', 'anode')
               .label('3', 'suppressor')
               .label('4', 'screen_R')
               .label('5', 'control')
        )
    elm.Line().down().at(tube.cathode).length(1)
    elm.Line().up().at(tube.anode).length(.5)
    elm.Line().left().at(tube.suppressor).length(1)
    elm.Line().right().at(tube.screen_R).length(1)
    elm.Line().left().at(tube.control).length(1)

A dual vacuum tube may be drawn, with independent number of grids on each side. Anchors are designated A on the left element and B on the right element. schemdraw.elements.tubes.DualVacuumTube

with schemdraw.Drawing():
    t = (elm.DualVacuumTube(grids_left=1, grids_right=3, heater=False)
             .label('anodeA', 'anodeA', halign='right')
             .label('anodeB', 'anodeB')
             .label('cathodeA', 'cathodeA')
             .label('cathodeB_R', 'cathodeB_R', halign='left')
             .label('gridA', 'gridA', valign='center')
             .label('gridB_1R', 'gridB_1R', valign='center')
             .label('gridB_3R', 'gridB_3R', valign='center')
        )

Sometimes, multiple tubes in one envelope are drawn in a split style. This may be enabled using split=’left’ or split=’right`.

with schemdraw.Drawing():
    tube1 = elm.Triode(split='left')
    elm.Line().down().at(tube1.cathode).length(1)
    tube2 = elm.Triode(split='right').at((2, 0))
    elm.Line().down().at(tube2.cathode_R).length(1)

Nixie Tubes are multi-anode tubes drawn with schemdraw.elements.tubes.NixieTube. The cathode may be cold, T or none and anodetype may be narrow or dot or none.

with schemdraw.Drawing():
    t = elm.NixieTube(anodes=12)
    for i in range(12):
        t.label(chr(ord('a')+i), f'anode{i}', halign='center', ofst=(0, .1))

    elm.NixieTube(anodes=6, anodetype='dot', cathode='cold', grid=True).at((0, -3.5))

Cables¶

schemdraw.elements.cables.Coax and schemdraw.elements.cables.Triax cables are 2-Terminal elements that can be made with several options and anchors. Coax parameters include length, radius, and leadlen for setting the distance between leads and the shell. Triax parameters include length, radiusinner, radiusouter, leadlen, and shieldofststart for offseting the outer shield from the inner guard.

Coax

Triax()

Coax(length=5, radius=0.5)

Triax(length=5, radiusinner=0.5)

CoaxConnect

Transformers¶

The schemdraw.elements.xform.Transformer element is used to create various transformers. The number of turns on each side is set with the t1 and t2 parameters. As integers, they define the total number of turns on that side. Multi-phase transformers may be created by setting t1 or t2 to a tuple of turns for each phase.

Transformer

Transformer(loop=True)

Transformer(core=False)

with schemdraw.Drawing():
    elm.Transformer(t1=10, t2=(2, 2), loop=True)

Basic Elements¶

Two-terminal¶

Resistors¶

IEEE Style¶

IEC/European Style¶

All Resistors¶

Capacitors and Inductors¶

Diodes¶

Miscellaneous¶

Sources and Meters¶

Box-Style Meters¶

Switches¶

Lines and Arrows¶

Single-Terminal¶

Power and Ground¶

Antennas¶

Connection Dots¶

Switches¶

Single-pole double-throw¶

Double-pole¶

Rotary Switch¶

DIP Switch¶

Audio Elements¶

Labels¶

Operational Amplifiers¶

Transistors¶

Bipolar Junction Transistors¶

Field-Effect Transistors¶

“Two-Terminal” Transistors¶

Vacuum Tubes¶

Cables¶

Transformers¶

Schemdraw

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