CADXChange

ResourcesElectrical schematic symbols

A thyristor battery charger, from AC input to battery, in one drawing

Breaker, fuses and line reactors, a six-thyristor bridge with its gate terminals, freewheel diode, filter reactor, shunt, varistor, voltmeter and battery, plus the firing unit with isolated gate outputs: parts from the Pro palette, placed and tagged on one sheet.

Free to use and modify in your own projects, including commercial ones. The ZIP holds the sample drawing, a template, a plot style table and a README; no add-in needed. The data in the drawing is made up, so it is not for design or construction. Provided as is, without warranty. Library terms (CXL-1.0)

Version 1.0 · updated November 14, 2026

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This sample uses these resources

The symbols are blocks from our own libraries, with their attributes filled in. The sheet and its title block come from our ISO A3 title block template. Download them to draw your own diagrams.

What is in the ZIP

  • Thyristor-Battery-Charger-Sample.dwg
    Sample drawing (DWG, AutoCAD 2018 format)
  • Electrical-Template-ISO-A3.dwt
    Template (DWT) that the drawing was made on
  • CADXChange-Monochrome.ctb
    Plot style table (CTB) that prints every colour black
  • README.txt
    README with the layer list and how to use the files

The template

The electrical template has 16 layers with colours, line weights and linetypes (power circuits, busbars, control, signal, protective earth, enclosure boundaries, text and more), the text styles ISO-2.5 to ISO-5, the dimension style ISO-25 and an ISO A3 layout with a title block and revision table. The layer names are a common convention, not a standard; rename them to match your company's rules.

Layers defined

Every layer in the template with its colour, line weight and linetype, and how many objects of this sample are on it. Layers the sample does not use are still defined, ready for your own drawing.

LayerColourLine weightLinetypeUsed forObjects here
Electrical layers
ELEC-POWER10.50 mmContinuousMain power circuits34
ELEC-BUS10.70 mmContinuousBusbars and heavy linesnot used here
ELEC-CONTROL40.25 mmContinuousControl circuitsnot used here
ELEC-SIGNAL30.18 mmContinuousSignal, instrumentation and communication circuits26
ELEC-PE20.35 mmContinuousProtective earth and bondingnot used here
ELEC-CABLE300.25 mmDASHEDCable, conduit and tray routesnot used here
SYMBOL70.25 mmContinuousSymbols (the layer the symbol libraries use)49
ELEC-TERMINAL70.25 mmContinuousTerminals and connection pointsnot used here
ELEC-BOUNDARY50.18 mmDASHDOTEnclosure, panel and device boundariesnot used here
ELEC-MECH-LINK80.18 mmDASHEDMechanical links, interlocks and measuring linksnot used here
ELEC-REF70.18 mmContinuousReference designations (-QF1, -K2)not used here
ELEC-WIRE-NO70.18 mmContinuousWire numbers and cable labelsnot used here
ELEC-XREF90.13 mmContinuousContact and cross reference textsnot used here
ELEC-TEXT70.18 mmContinuousGeneral text128
ELEC-NOTES70.18 mmContinuousNotes and legends7
ELEC-DIM30.18 mmContinuousDimensionsnot used here
Sheet and symbol layers
07defaultContinuousDefault layer, keep it emptynot used here
FRAME7defaultContinuousSheet border5
TITLEBLOCK7defaultContinuousTitle block and revision table1
VIEWPORT8defaultContinuousLayout viewport frame (does not plot)2
DRAWING-AREA8defaultContinuousBoundary of the model drawing area (does not plot)2

Styles defined

The text styles, the dimension style and the linetypes that the template defines, so you do not have to set them up in each new drawing.

KindNameSettings
Text styleISOisocp.shx, 15°, variable height
Text styleISO-2.5isocp.shx, 15°, 2.5 mm high
Text styleISO-3.5isocp.shx, 15°, 3.5 mm high
Text styleISO-5isocp.shx, 15°, 5 mm high
Text styleTB-enArial, used by the title block
Dimension styleISO-25Text 2.5 mm, arrows 2.5 mm, extension lines 1.25 mm beyond the dimension line and 0.625 mm from the object, dimension lines 3.75 mm apart, 0 decimals
LinetypeContinuousSolid line
LinetypeDASHEDDashed
LinetypeDASHDOTDash-dot
LinetypeCENTERCentre line
LinetypePHANTOMPhantom line
LinetypeHIDDENHidden line

Sheet and drawing setup

How the sheet is set up, so your own drawings print the same way.

Sheet
ISO A3 landscape, 420 × 297 mm.
Layout
One layout named ISO-A3, plotted at 1:1 on full-bleed A3 media, so the sheet has no printer margin.
Border
20 mm from the left edge (binding side) and 10 mm from the other edges; the drawing area inside is 390 × 277 mm.
Model space
Units are millimetres. The drawing area is shown at 1:1, so 1 mm in the drawing is 1 mm on paper.
Title block
160 × 79 mm at the lower right, with a four-line revision table above the company, project, title and approval fields.
Text size
2.5 mm for labels and notes, 3.5 mm and 5 mm for headings.
Linetype scale
1, so dashes are sized for plotting at 1:1.
Plot style
None set. Pick the CTB from the ZIP in the page setup for black-and-white plots.

Title block fields

The attributes of the title block.

AttributeField on the sheetValue in this sample
COMPANYCOMPANYCADXChange
PROJECTPROJECTBattery charger, 110 V DC
AREAAREAAC input to battery
SYSTEMSYSTEM400 V AC / 110 V DC
CLIENTCLIENTSample
TITLEDRAWING TITLEControlled rectifier schematic
DRAWING_NODRAWING NO.E-891
CONTRACT_NOCONTRACT NO.—
REVREVA
DRAWNDRAWN—
CHECKEDCHECKED—
APPROVEDAPPROVED—
DATEDATE2026-11-15
SCALESCALENTS
SHEETSHEET1
SHEET_OFOF1

Revision table: R1 to R4, each with REV, DATE, DESCRIPTION and BY (16 attributes, empty in this sample).

Blocks in the drawing

The equipment list of the drawing: block name, symbol and how many times it is placed.

SymbolBlockPlaced
Junction dotIEEE_T_JUNCTION_DOT13
Circuit terminalIEEE_K_TERMINAL9
Thyristor, N gate, style 3IEEE_SC_SCR_N_36
Photon-coupled isolatorIEEE_SC_ISOLATOR6
Fuse, rectangleIEEE_FUSE_BOX4
Inductor, reactorIEEE_INDUCTOR4
Circuit breaker, three polesIEEE_BREAKER_3P1
Semiconductor diodeIEEE_SC_DIODE1
Instrument or relay shuntIEEE_R_SHUNT_INSTRUMENT1
Varistor, box formIEEE_R_VARISTOR_BOX1
VoltmeterIEEE_METER_V1
Battery, three cellsIEEE_BATTERY_3CELL1
Thermistor, negative coeff.IEEE_R_THERMISTOR_NTC1

How to use it

  1. Open the sample drawing to see how layers, text and the title block are used, or open it in the browser first, nothing to install.
  2. Start your own drawing from the template (NEW, then pick the DWT file). Copy the CTB file to your plot styles folder if you want black-and-white plots.
  3. Insert blocks from the symbol library into your drawing. The blocks in the sample are copies; they do not change when a library changes.

Frequently asked questions

Can I use the drawing for a real project?
As a starting point for layout and layers, yes. The ratings, settings and cable sizes are made up, so the diagram has to be checked and changed for your project before it is used for design or construction.
Why are the layers coloured?
Colours and line weights follow the layers: power circuits are red and heavy, control is cyan, signal is green. The plot style table in the ZIP prints everything black and keeps the line weights, so you can plot in black and white as well.
Which CAD programs open it?
The drawing and the template are in AutoCAD 2018 format, which AutoCAD 2018 and later open, and so do other CAD programs that read this format. The browser viewer needs nothing installed.