Easy

Continuity Tester / Cable Checker

A buzzer powered through a cable under test sounds only if the two ends are electrically connected — the basic tool for checking whether a cable, fuse, or solder joint "still works."

Circuit Diagram

9V battery + − BUZZER probe A probe B touch probes together (or across the cable/fuse under test) Buzzer sounds only when the probes are electrically connected

How to Build It

  1. Connect one buzzer terminal to the positive rail (through a 9V battery).
  2. Connect the buzzer's other terminal to a test lead (a probe).
  3. Connect the other probe to GND.
  4. Touch the two probes together — the buzzer should sound immediately.
  5. Use the probes to check a cable, fuse, or solder joint — the buzzer sounds only if there's electrical continuity.

Bill of Materials

ProductCodeQty
Buzzer LD-BZPG-2312 1
Dupont jumper wire — 2
← All kits  ·  Newsletter