Intermediate

Bench Power Supply

Assemble a low-voltage adjustable bench supply using a DC-DC module and protected output terminals.

Safety first, always.

ElectroLab AI teaches theory, low-voltage electronics, and planning concepts. Mains voltage, switchboards, fixed wiring, high-current systems, and legal electrical work must only be performed by licensed electricians where required.

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Bench tool blueprint

Build a protected adjustable DC supply for testing small electronics without guessing at the power rails.

Bench time

3-5 hours

Typical parts

$45-$90 AUD

Power

Approved external DC adapter

You finish with

Adjustable low-voltage bench supply

Before the first wire

Know the build before you power it.

Use an approved plug-pack or laptop-style DC brick. Do not put mains wiring inside this project.

Pick a buck/boost module with voltage and current display, current limiting, and ratings above your expected load.

Fit the fuse before the control module so a wiring fault opens before thin internal wires overheat.

Use this supply for low-voltage electronics only and label the maximum input, output, and current clearly.

Bill of materials

8 parts groups to gather

Check every spec

Qty	Part	Exact spec	What it does	Inspect before use
1	External DC adapter	12-24 V DC output, approved and insulated	Provides safe isolated input power.	No cracked case, damaged lead, or unknown polarity.
1	Adjustable DC-DC module	Buck/boost or buck module with current limit	Sets output voltage and current.	Read the IN/OUT labels and cooling requirements.
1	Input fuse	2-5 A automotive or panel fuse sized for the adapter	Protects internal wiring.	Fuse holder grips firmly and is insulated.
1	Power switch	DC-rated switch above adapter current	Disconnects the module input.	Use continuity mode to find the switched contacts.
2	Binding posts	Red and black, insulated	Makes a repeatable output connection.	No exposed metal touches the enclosure.
1	Output protection diode or MOSFET module	Reverse-current protection suitable for output current	Reduces damage from a connected battery or charged capacitor.	Confirm direction and voltage drop before final mounting.
1	Enclosure and vents	Plastic or earthed metal with strain relief	Keeps wiring secure and cool.	Module heat sink has airflow and no wire can rub on sharp edges.
As needed	Wire and labels	Red/black power wire sized for current	Makes the current path easy to inspect.	Crimps or solder joints are strain-relieved and heat-shrunk.

Build boundary

This guide uses an external approved DC source. It does not cover building mains-powered supplies, modifying power adapters, or working inside switch-mode supplies.

Part modules vary. Read the markings and datasheet for the exact board in front of you before applying power.