All articles
Everything on Copper & Signal, organised by topic.
Soldering & Repair
- Battery-Powered Electronics Project Safety — Treat a battery project as a complete documented system: compatible cells or pack, approved charger, protection, wiring, connectors, load, enclosure, and…
- How to Clean Flux Residue Safely — Identify the flux first and confirm that the cleaner is compatible with the board and components.
- Desolder a Component Without Board Damage — Document component orientation, disconnect every source, handle stored energy by the documented method, and use fume capture, eye protection, a stable…
- Diagnose a Low-Voltage Device With No Power — Troubleshoot only a known, isolated low-voltage device. Record the symptom, then verify the supply voltage, polarity, pinout, current capability,…
- How to Inspect a PCB for Damage — Inspect a PCB only after identifying its equipment and energy sources, limiting the work to known isolated low voltage, disconnecting power and batteries,…
- How to Prepare and Maintain a Soldering Tip — Prepare a soldering tip with the station maker approved tip, temperature range, cleaning method, alloy, and flux.
- How to Recognize a Good Solder Joint — A good solder joint wets both pad and lead, forms the required connection without hiding the interface, preserves the component and board, and has no…
- Repair a Broken Low-Voltage Wire or Connector — Repair a broken wire only in a known isolated low-voltage system after identifying voltage, current, polarity, signal, shielding, temperature, flex, and…
- Replace an Electrolytic Capacitor Safely — Replace an electrolytic capacitor only on a documented isolated low-voltage board.
- When Not to Repair Electronics Yourself — Do not repair equipment when its energy sources or discharge procedures are unknown; when mains, high voltage, batteries, interlocks, isolation, or stored…
Project Fundamentals
- Bench Power-Supply Current Limit Basics — Set a bench power-supply current limit from the circuit documented startup demand, normal load, component limits, and fault tolerance, not from a…
- Breadboard Connections Explained — A solderless breadboard joins hidden groups of holes, but row and rail patterns vary and power rails may be split.
- Capacitor Types and Polarity Basics — Choose a capacitor by its circuit role, capacitance, tolerance, voltage and waveform limits, dielectric, polarity, temperature, ESR, ripple-current needs,…
- How to Choose an LED Series Resistor — For a simple DC LED indicator, subtract the LED forward voltage from the supply voltage, then divide that result by the target current to estimate series…
- How to Continuity-Test a Circuit Safely — Continuity mode applies a small test signal and reports a path below the meter threshold; a beep does not prove zero resistance, current capacity, correct…
- Diode, Transistor, and MOSFET Basics — A diode steers current within specified limits, a BJT uses base current to influence collector current, and a MOSFET uses gate-to-source voltage to…
- Multimeter Modes and Lead Jacks Explained — Inspect the multimeter and read its manual before measuring. Voltage mode connects in parallel with the red lead in the voltage jack.
- How to Read an Electronic Schematic — Read an electronic schematic as a map of connected electrical nodes, not a picture of physical placement.
- Resistor Value and Power Rating Explained — Choose a resistor by confirming its nominal resistance, tolerance, power rating, working-voltage limit, pulse behavior, construction, package, temperature…
- Set Up a Safe Low-Voltage Electronics Bench — Build a hobby electronics bench around known, isolated, current-limited low-voltage circuits.