A PhET Circuit Construction Kit alternative with a breadboard and lab instruments

This page is for teachers and students who know the Circuit Construction Kit simulations from PhET and want to see what else exists for circuit work, or whether DCACLab fits next to them.

DCACLab is a different kind of tool from PhET's simulations: a circuit lab in the web browser with a breadboard mode, bench-style instruments and classes for assignments. A course can use both.

What the Circuit Construction Kit does well

PhET simulations are free, interactive and research-based, and they are open source.
They are built in HTML5, so they run online in a browser or can be downloaded.
Circuit Construction Kit: DC lets students build circuits from batteries, resistors, light bulbs, fuses and switches, and measure them with an ammeter and a voltmeter.
Circuit Construction Kit: AC adds AC voltage sources, capacitors and inductors, and graphs current and voltage against time.
Students can switch between a schematic view and a lifelike view, and there are Virtual Lab versions of the DC and AC kits.
PhET publishes a teacher tips guide for the DC kit.

Where DCACLab is different

Components: sources, resistors, capacitors, inductors and potentiometers; diodes, LEDs, bipolar transistors and MOSFETs; operational amplifiers, transformers, relays and switches; logic gates and integrated circuits.
Bench-style instruments: digital and analog multimeters, an oscilloscope and a wattmeter.
A breadboard mode, where students place parts and jumper wires as they would on a real breadboard.
An IC Creator for making your own integrated circuits (not included in the Starter plan).
Saving and sharing circuits, with a plan or as part of a class.
Classes: create a classroom, share its join link, assign a circuit with a due date, then open each submission and enter a mark.
Ready-to-use lab activities, each with steps, a data table, questions and an answer key.

Comparison at a glance

Where it runs: Circuit Construction Kit: HTML5 simulation, online or downloaded.; DCACLab: in a web browser.
Components: Circuit Construction Kit: parts include batteries, resistors, light bulbs, fuses and switches (DC); AC voltage sources, capacitors and inductors (AC).; DCACLab: sources, passive parts, diodes, LEDs, transistors, MOSFETs, op-amps, transformers, relays, switches, logic gates and integrated circuits.
Measuring: Circuit Construction Kit: includes an ammeter and a voltmeter (DC kit) and graphs of current and voltage against time (AC kit).; DCACLab: digital and analog multimeters, an oscilloscope and a wattmeter.
How the circuit looks: Circuit Construction Kit: schematic view or lifelike view.; DCACLab: components on a board, plus a breadboard mode.
For teachers: Circuit Construction Kit: a teacher tips guide from PhET.; DCACLab: classrooms with a join link, assignments with due dates, and grading.
Access: Circuit Construction Kit: free.; DCACLab: a limited demo that cannot save; saving needs a plan; classrooms run under a school or institutional license, and teachers can try one with the free classroom demo.

When to choose the Circuit Construction Kit instead

You want a free simulation for a first look at current and voltage in simple circuits.
You want an open-source simulation, or one you can download.
Your lesson is built around PhET's teacher tips guide.
You only need the DC or AC basics the kits cover, without a breadboard or bench instruments.

How to try DCACLab

For students

Create an account and open the lab in your web browser. Without a plan it is a demo: circuits cannot be saved, and a circuit can have at most two components of each type.

Create an account

Teaching with circuits?

Create a classroom, assign circuits for your students to build, and review what they hand in. The free classroom demo gives you one classroom with room for 30 students for 7 days, counted from when your first student joins (once per teacher); after that it keeps up to 5 students.

Try the free classroom demo

Frequently asked questions

Does DCACLab replace PhET?

It does not have to. A course can use both: the Circuit Construction Kit for a first look at current and voltage, and DCACLab for breadboard work, multimeters, the oscilloscope and parts such as transistors and op-amps.

Is DCACLab free?

You can use the lab free as a demo: circuits cannot be saved, and a circuit can have at most two components of each type. Saving needs a plan. Teachers can try a free classroom demo: one classroom with room for 30 students for 7 days, counted from when the first student joins (once per teacher); after that, the classroom keeps up to 5 students.

Can students hand in their work?

Yes, in a DCACLab class. The teacher assigns a circuit, each student gets their own copy to work on, and the teacher opens each submission and enters a mark.

Do students need to install anything?

No. DCACLab runs in a web browser.

Sources

Facts about other products come from their official websites, checked on 3 November 2026.

PhET is a trademark of the Regents of the University of Colorado. DCACLab is not affiliated with, sponsored or endorsed by the University of Colorado or PhET Interactive Simulations.