Design Your Electronic Project Using an Online Circuit Builder

In this tutorial you’ll use an online circuit designer (Circuit Builder with Component Icons) to draw and assemble a compact DC motor power-supply block: mains/adapter input, bridge rectifier with smoothing capacitor, pushbutton, current-limiting resistor, inline ammeter and the motor. No code or soldering required for the drawing — the guide shows how to plan, document and export a clear wiring diagram you can use for a bench build.

These are example values for a small DC motor application — adapt to your motor specs.

1. 12 VAC mains adapter or 12 VAC transformer (secondary) → chosen so rectified DC ≈ 16–17 V no-load
2. Bridge rectifier (single packaged or 4 × 1N5408 for higher current)
3. Smoothing capacitor: 2200–4700 µF, 25 V electrolytic
4. Start/stop pushbutton (normally open)
5. Current limiting resistor (optional): 10 Ω, 5 W (for soft start or to limit stall current)
6. Ammeter (panel or inline, rated for expected current)
7. DC motor (12–24 V rated depending on your supply)
8. Screw terminals or terminal block for connections
9. Inline fuse (e.g. 2–5 A slow-blow depending on motor)
10. Hook-up wire, heat-shrink, basic tools, multimeter

Open the Circuit Builder: https://procalclab.com/circuit-builder-with-component-icons

Create a new canvas/project and give it a name like Motor Power Supply – v1.

Drag a 2-pole terminal block (labelled AC IN or Adapter) to the left side of the canvas.

Add a small text label: 12 VAC IN. This represents your adapter/transformer secondary or adapter jack.

Drag a bridge rectifier component or four diodes arranged as a bridge. If the builder offers a packaged bridge symbol, use it.

Connect the two AC input terminals to the bridge AC pins (~ and ~).

Label the bridge DC outputs + and –.

Place an electrolytic capacitor between + and – on the DC side.

Set the value to 2200 µF – 4700 µF, 25 V in the component properties. Ensure polarity is correct: the capacitor negative goes to –.

On the + rail, add an inline fuse near the input. Choose a rating slightly above your expected running current.

After the fuse, add a pushbutton (normally open) or a toggle switch for start/stop.

Insert the current limiting resistor (e.g. 10 Ω, 5 W) on the + rail after the switch. This helps soften motor inrush and protect the supply.

Immediately after the resistor add an ammeter symbol in series so you measure motor current. If using a panel ammeter, place a shunt symbol and label its rating.

Connect the motor positive terminal to the ammeter output; connect the motor negative to the – rail.

Optionally add a flyback diode across a DC motor (if you plan to drive via a transistor or H-bridge later). For a brushed DC motor powered by a rectified DC with smoothing capacitor, the capacitor and the motor form the normal load — a diode across the motor is still good practice for inductive spikes if the motor is switched rapidly.

Use the builder’s text labels to record component types and values (e.g., Bridge: KBPC5010, C1: 4700µF / 25V, R1: 10Ω / 5W, Fuse: 3A).

Add a note about expected no-load and stall current for the motor. This helps choose the fuse and ammeter range.

Use the tool’s export function to save a PNG/SVG of the schematic. Save step images for your Instructables post.

Where this diagram helps

1. Use the exported diagram as a wiring map for bench assembly.
2. If you build a PCB or panel, the visual BOM and clear labels speed up layout and ordering parts.
3. The same approach works for other small motor systems: change component ratings and fuses to suit the motor.

This quick exercise shows how an online circuit builder can be used not just to draw schematics, but to plan safe, testable wiring for small DC systems. You can try the tool and reproduce this exact diagram here:

https://procalclab.com/circuit-builder-with-component-icons