Safety Basics

A short list worth reading before your first project.

• Stay on low-voltage DC (battery or USB power) until you're experienced — mains AC can be lethal and needs separate training.
• Double-check polarity before powering a circuit; reversed batteries or backwards electrolytic capacitors can fail suddenly.
• Never bridge the two terminals of a battery directly with wire — a short circuit can overheat fast, especially with rechargeable cells.
• Let a soldering iron cool in its stand, never on the bench, and keep it away from cables and skin.
• Work on a non-flammable surface with a bit of ventilation, especially while soldering.

None of this is meant to be alarming — low-voltage electronics is one of the safest hands-on hobbies there is, as long as you respect these few basics.