Skip to content
ohmplay. Electronics
laboratory

Home / Teachers

OhmPlay in the classroom

First a prediction. Then the circuit.

Fourteen tools and three experiments for teaching electronics, logic, control and motion. Share exercises with their values, project them or embed them in your learning platform. Students do not need an account.

A sequence for your lesson

  1. Ask a question. For example: “If I load this divider, will it still output 2.5 V?” Ask for a prediction and a reason before showing the result.
  2. Fix the conditions. Share the exercise link. Each team records what stays fixed, what changes and the units used.
  3. Change one variable. Compare two states numerically. Animation can be paused; the drawing does not have to move to explain the circuit.
  4. Explain and compare. Ask for a formula, numerical substitution and a sentence connecting cause with effect. Use the tool’s result as a check.

Ask for three pieces of evidence: the initial prediction, a numerical comparison and an explanation of one model limitation. OhmPlay does not store submissions, answers or grades. Collect them in notebooks or your existing learning platform.

Choose a topic and a question

DC circuits

Start with proportional reasoning, units and simple equations. Suitable for introductory middle-school or high-school activities and for review in technical or college courses.

Supporting resources: units and prefixes, choosing an LED resistor and the loaded-divider experiment.

Capacitors and time

Suitable for high-school and college courses. Start with ratios and graph reading; the exponential extension requires that mathematical background.

Continue with time to a target voltage and the 90% experiment.

Logic and number representation

An accessible starting point for middle-school and high-school technology classes: begin with two switches and small numbers.

Mechanisms and robotics

Explore ratios and rotation direction in middle-school or high-school technology classes; add angles, coordinates and resolution in advanced technical or college work.

  • Gears: distinguish speed reduction from direction reversal; compare external meshing with an internal ring gear.
  • Stepper motor: separate command rate, steps per revolution and rpm.
  • Planar two-joint arm: find two configurations for a target and explain an unreachable point.

Supporting resources: transmission ratio, full steps and half steps and the resolution-and-speed experiment.

Control and feedback

For learners comfortable with graphs, algebra and response over time: advanced technical courses and college.

PID simulator: compare two settings with the same first-order plant, setpoint and actuator limits. Use the tuning guide to distinguish persistent error from saturation. A simulation does not replace identifying a real plant or checking its stability and safety.

Match the activity to your group

These are suggested teaching uses, not official curriculum alignments or institutional endorsements. Choose activities based on prior knowledge and your course objectives.

Middle school

Use Ohm’s law, LEDs, color bands and logic gates; add simple gear ratios or binary numbers as appropriate. Begin with V and Ω before introducing prefixes. Evidence: predict the effect of doubling R, and explain OR versus XOR using one truth-table row.

High school

Use equivalent resistance, a loaded divider and RC. Introduce mA and µF and require unit conversion before substitution. Evidence: compare 2.5 V with 1.667 V in the divider and identify the changed condition. Advanced electives can extend this to motor sequences and feedback.

College

Compare mesh equations, capacitor energy, RC response, PID saturation and 2R inverse kinematics. Evidence: derive a result, check it numerically and explain singularities or assumptions that limit the model.

Three activities with checks

1 · The divider that stops giving half

Question: with 5 V and two 1 kΩ resistors, what will a 1 kΩ load do? Keep the supply, R1 and R2 fixed; change only the load connection. Open the initial conditions.

Result and follow-up question

Without a load, output is 2.5 V. Loading R2 with an equal resistor gives 500 Ω: Vsal = 5 × 500 / (1000 + 500) = 1.667 V. Ask where the additional current flows and why a divider is not a regulated supply.

Open the guided divider activity ↗

2 · One time constant is not 90%

Question: with R = 10 kΩ and C = 100 µF, how long does charging from 0 V to 90% of 5 V take? Then double only R. Open the curve at one time constant.

Result and follow-up question

τ = RC = 1 s. At 1 s, voltage is 3.161 V, about 63.2%. Reaching 90% takes −τ ln(0.1) = 2.303 s. Doubling R gives 4.605 s; ideal final voltage remains 5 V. Ask students to plot both curves against the same time axis.

Open the guided 90% activity ↗

3 · More resolution at the same command rate

Question: a motor with 200 full steps per revolution receives 100 commands/s. Does half-stepping make it faster? Keep command rate fixed. Open the motor in full-step mode.

Result and follow-up question

Full-step: 1.8° per command and 30 rpm. Half-step: 0.9° and 15 rpm. Restoring 30 rpm in half-step mode requires 200 commands/s. The model assumes the rotor follows every command and excludes missed steps, load and resonance.

Open the guided steps-and-speed activity ↗

Link, embed or projector

  1. Open a tool, adjust its values and check the result.
  2. In Use it in your classroom, choose Copy link with current values to send that exact exercise. Links do not store answers or running animations.
  3. Choose Copy embed code if your platform permits HTML. Paste the entire block: a frame followed by a normal link to OhmPlay’s explanations.
  4. For a presentation, select Projector mode in the full tool. Exit with Escape or the same button. If fullscreen is blocked, open the direct link and use browser zoom.

The embedded version shows only the tool, without ads or ad slots. Its footer opens the full explanation in a new tab. Keep a normal text link outside the frame too, so students can continue if embedding is blocked.

Share only exercise numbers and options, never names or email addresses in the URL. When opened, those values form part of the address and may remain in browser history and hosting logs.

Bring it into your learning platform

Editor options and permissions vary. Check the student view before using the activity. A direct link is the fallback if the platform removes embed code.

Google Sites

In the Insert panel, open the embed option and choose Embed code and paste the OhmPlay block. Preview and insert it, then adjust height to show controls and footer. Also add a normal Sites text-box link outside the embed block to open the full tool. Official Sites help.

Moodle

Enable course editing and add a Page. In the content editor, open HTML mode and paste the full code. Save and check the student view. If the iframe disappears after saving, ask the administrator about content permissions, or use a URL resource with the exercise link. There is no need to disable campus security protections. Moodle Page resource.

Blogger

Create a post with the question and a link to the exercise. If your editor offers HTML view, paste the embed block there outside other paragraphs. Check Preview and keep the normal link after the iframe. If code appears as text, return to HTML editing; if saving removes the embed, use the direct link. Editing and previewing posts.

WordPress

Use a Custom HTML and paste the full code. Check that the iframe survives saving. Self-hosted WordPress may remove it depending on user permissions. WordPress.com restricts advanced code according to enabled features; if unavailable, use a paragraph link. Sharing a URL does not require buying a plan. Custom HTML in WordPress and WordPress.com embedding restrictions.

Google Classroom: share the link

For OhmPlay, use an exercise link in Classroom rather than pasting an iframe into a description. In Classwork, create a Material or assignment and choose Add → Link. Paste the copied URL with its values and include the question students should answer. Attaching links in Classroom.

Instructions were checked against platform documentation, not tested in school accounts. Administrators may restrict external content.

From the on-screen result to understanding

Models are ideal and each tool states its limits. Real resistors have tolerance and temperature effects; motors can miss steps; real arms encounter obstacles. Ask students to identify at least one simulation–hardware difference before building.

For slower connections, prepare one tool and its explanation first. There is no registration, progress tracking or program download. Full-page formulas and exercises remain readable if JavaScript fails; interactive controls require it. See what an ideal model leaves out.